Unlocking Layer and Method

ABSTRACT

A system and method for anti-reflective layers is provided. In an embodiment the anti-reflective layer comprises a polymer resin which has repeating units within it. At least one of the repeating units comprises a locked unit which has a cyclic structure and a lock within the unit. After the anti-reflective layer has been applied and baked, irregularities such as voids and step heights differences that have occurred may be handled by unlocking the lock within the locked unit. This unlocking breaks the cyclic structure, allowing the polymer to take up more volume and causing the anti-reflective layer to self-expand, filling the voids and reducing the step-height. The unlocking may be performed by exposure or thermal treatments.

This application claims the benefit of U.S. Provisional Application No.61/777,692, filed on Mar. 12, 2013, entitled Anti-Reflective LayerMethod, which application is hereby incorporated herein by reference.

BACKGROUND

As consumer devices have gotten smaller and smaller in response toconsumer demand, the individual components of these devices havenecessarily decreased in size as well. Semiconductor devices, which makeup a major component of devices such as mobile phones, computer tablets,and the like, have been pressured to become smaller and smaller, with acorresponding pressure on the individual devices (e.g., transistors,resistors, capacitors, etc.) within the semiconductor devices to also bereduced in size.

One enabling technology that is used in the manufacturing processes ofsemiconductor devices is the use of photolithographic materials. Suchmaterials are applied to a surface and then exposed to an energy thathas itself been patterned. Such an exposure modifies the chemical andphysical properties of the exposed regions of the photolithographicmaterial. This modification, along with the lack of modification inregions of the photolithographic material that were not exposed, can beexploited to remove one region without removing the other.

However, as the size of individual devices has decreased, processwindows for photolithographic processing as become tighter and tighter.As such, advances in the field of photolithographic processing, such asthe use of anti-reflective layers to prevent undesired reflections ofimpinging light, have been necessitated in order to keep up the abilityto scale down the devices, and further improvements are needed in orderto meet the desired design criteria such that the march towards smallerand smaller components may be maintained.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present embodiments, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates a bottom anti-reflective layer on a semiconductorsubstrate in accordance with an embodiment;

FIG. 2 illustrates baking of the bottom anti-reflective layer inaccordance with an embodiment;

FIGS. 3A-3B illustrate an unlocking and an expansion of the material ofthe anti-reflective layer in accordance with an embodiment;

FIG. 4 illustrates an exposure process to unlock the material of theanti-reflective layer in accordance with an embodiment;

FIG. 5 illustrates one possible reaction mechanism that may be used tounlock the material of the anti-reflective layer in accordance with anembodiment;

FIG. 6 illustrates a baking process to unlock the material of theanti-reflective layer in accordance with an embodiment;

FIGS. 7A-7B illustrate an application, exposure, and development of aphotoresist in accordance with an embodiment; and

FIGS. 8A-8B illustrate a use of the anti-reflective layer as anunderlayer in a tri-layer process in accordance with an embodiment.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to clearly illustrate the relevant aspects of the embodiments andare not necessarily drawn to scale.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The making and using of the present embodiments are discussed in detailbelow. It should be appreciated, however, that the present disclosureprovides many applicable inventive concepts that can be embodied in awide variety of specific contexts. The specific embodiments discussedare merely illustrative of specific ways to make and use the disclosedsubject matter, and do not limit the scope of the different embodiments.

Embodiments will be described with respect to a specific context, namelya self-expanding bottom anti-reflective coating utilized in themanufacturing of semiconductor devices at a 28 nm process node orsmaller, such as a 20 nm process node or even a 16 nm process node.Other embodiments may also be applied, however, to other coatings indifferent processes.

With reference now to FIG. 1, there is shown a semiconductor device 100with a substrate 101 with fins 103 formed over the substrate 101 and abottom anti-reflective coating (BARC) layer 105 applied over the fins103 and the substrate 101. The substrate 101 may comprise bulk silicon,doped or undoped, or an active layer of a silicon-on-insulator (SOI)substrate. Generally, an SOI substrate comprises a layer of asemiconductor material such as silicon, germanium, silicon germanium,SOI, silicon germanium on insulator (SGOI), or combinations thereof.Other substrates that may be used include multi-layered substrates,gradient substrates, or hybrid orientation substrates.

The fins 103 will serve as a fin structure for the eventual formation ofFinFET or multiple gate transistors (not separately illustrated in FIG.2A) in, e.g., a 16 nm FinFET process. In an embodiment the fins 103 maybe formed from the material of the substrate 101 and, as such, may alsocomprise bulk silicon, doped or undoped, or be an active layer of a SOIsubstrate. The fins 103 may be formed by first applying a maskingmaterial over the substrate 101, patterning the masking material, andthen using the masking material as a mask to etch into the substrate101, thereby forming the fins 103 from the material of the substrate101.

However, using the material of the substrate 101 to form the fins 103 isonly one illustrative method that may be used to form the fins 103.Alternatively, the fins 103 may be formed by initially depositing asemiconductor material, such as silicon, silicon-germanium, or the like,over the substrate 101 and then masking and etching the semiconductormaterial to form the fins 103 over the substrate 101. In yet anotheralternative, the fins 103 may be formed by masking the substrate 101 andusing, e.g., an epitaxial growth process to grow the fins 103 on thesubstrate 101. These, and any other suitable method for forming the fins103 may alternatively be utilized, and all such methods are fullyintended to be included within the scope of the embodiments.

The BARC layer 105 is applied over the fins 103 and fills the regionsbetween the fins 103 in preparation for an application of a photoresist701 (not illustrated in FIG. 1 but illustrated and described below withrespect to FIG. 7). The BARC layer 105, as its name suggests, works toprevent the uncontrolled and undesired reflection of energy (e.g.,light) such as light back into the overlying photoresist 701 during anexposure of the photoresist 701, thereby preventing the reflecting lightfrom causing reactions in an undesired region of the photoresist 701.Additionally, the BARC layer 105 may be used to provide a planar surfaceover the substrate 101 and the fins 103, helping to reduce the negativeeffects of the energy impinging at an angle.

In an embodiment the BARC layer 105 comprises a polymer resin, acatalyst, and a cross-linking agent, all of which are placed into asolvent for dispersal. The polymer resin comprises a polymer chain withrepeating units, wherein at least one of the repeating units is alocking monomer with a locked structure. This locked structure, whenunlocked, releases the monomer to expand, thereby expanding the polymerin which the monomer is located.

In an embodiment the locked structure is a ring structure that has atleast one lock 301 (one example of which is illustrated below in FIG. 3)or locking bond within it. The lock 301 may be a covalent bond that iscleavable by a product of the catalyst (described further below) that isanother component of the BARC layer 105. However, in alternativeembodiments the lock could comprise any kind of alternative bonding,such as a dipole-dopole interaction, a hydrogen bond, or a metallicbond.

In an embodiment in which the lock is a covalent bond, the lock 301within the locked structure may have the following structure:

where Rx, Rz, or Ry is a hydrogen, halogen, an alkyl group having acarbon number of 1 to 20, an aminoalkyl group having a carbon number of1 to 20, an alkoxy group having a carbon number of 1 to 20, anaminoalkyl group having a carbon number of 1 to 20 a hydroxyalkyl grouphaving a carbon number of 1 to 20, a substituted or unsubstituted arylgroup having a carbon number of 1 to 20, or a thioalkyl group having acarbon number of 1 to 20.

Specific examples of an alkyl group that may be used for Rx, Rz, or Ryinclude methyl group, an ethyl group, an n-propyl group, an isopropylgroup, a cyclopropyl group, an n-butyl group, an isobutyl group, ans-butyl group, a tert-butyl group, a cyclobutyl group, a1-methyl-cyclopropyl group, a 2-methyl-cyclopropyl group, an n-pentylgroup, a 1-methyl-n-butyl group, a 2-methyl-n-butyl group, a3-methyl-n-butyl group, a 1,1-dimethyl-n-propyl group, a1,2-dimethyl-n-propyl group, a 2,2-dimethyl-n-propyl group, a1-ethyl-n-propyl group, a cyclopentyl group, a 1-methyl-cyclobutylgroup, a 2-methyl-cyclobutyl group, a 3-methyl-cyclobutyl group, a1,2-dimethyl-cyclopropyl group, a 2,3-dimethyl-cyclopropyl group, a1-ethyl-cyclopropyl group, a 2-ethyl-cyclopropyl group, an n-hexylgroup, a 1-methyl-n-pentyl group, a 2-methyl-n-pentyl group, a3-methyl-n-pentyl group, a 4-methyl-n-pentyl group, a1,1-dimethyl-n-butyl group, a 1,2-dimethyl-n-butyl group, a1,3-dimethyl-n-butyl group, a 2,2-dimethyl-n-butyl group, a2,3-dimethyl-n-butyl group, a 3,3-dimethyl-n-butyl group, a1-ethyl-n-butyl group, a 2-ethyl-n-butyl group, a1,1,2-trimethyl-n-propyl group, a 1,2,2-trimethyl-n-propyl group, a1-ethyl-1-methyl-n-propyl group, a 1-ethyl-2-methyl-n-propyl group, acyclohexyl group, a 1,4-dimethyl-cyclohexyl group, a1-methyl-cyclopentyl group, a 2-methyl-cyclopentyl group, a3-methyl-cyclopentyl group, a 1-ethyl-cyclobutyl group, a2-ethyl-cyclobutyl group, a 3-ethyl-cyclobutyl group, a1,2-dimethyl-cyclobutyl group, a 1,3-dimethyl-cyclobutyl group, a2,2-dimethyl-cyclobutyl group, a 2,3-dimethyl-cyclobutyl group, a2,4-dimethyl-cyclobutyl group, a 3,3-dimethyl-cyclobutyl group, a1-n-propyl-cyclopropyl group, a 2-n-propyl-cyclopropyl group, a1-isopropyl-cyclopropyl group, a 2-isopropyl-cyclopropyl group, a1,2,2-trimethyl-cyclopropyl group, a 1,2,3-trimethyl-cyclopropyl group,a 2,2,3-trimethyl-cyclopropyl group, a 1-ethyl-2-methyl-cyclopropylgroup, a 2-ethyl-1-methyl-cyclopropyl group, a2-ethyl-2-methyl-cyclopropyl group and a 2-ethyl-3-methyl-cyclopropylgroup.

Specific examples of an aminoalkyl group that may be used for Rx, Rz, orRy include an aminomethyl group, an aminoethyl group, and an aminopropylgroup.

Specific examples of an alkoxy group that may be used for Rx, Rz, or Ryinclude a methoxy group, a ethoxy group, a n-propoxy group, an-propyloxy group, a i-propyloxy group, a iso-propoxy group, a n-butoxygroup, a iso-butoxy group, a sec-butoxy group, a tert-butoxy group, an-pentoxy group, a n-hexoxy group, a n-octoxy group, a n-nonanoxy group,a n-decylkoxy group, a n-butyloxy group, a t-butyloxy group, a2-ethylhexyloxy group, a n-decyloxy group, a phenethyloxy group and aphenoxyethoxy group.

Specific examples of an hydroxyalkyl group that may be used for Rx, Rz,or Ry include a hydroxymethyl group, a 1-hydroxyethyl group, a2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl groupand a 3-hydroxypropyl group.

Specific examples of an hydroxyalkyl group that may be used for Rx, Rz,or Ry include a phenyl group, a naphthyl group, a biphenyl group, a2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, acumenyl group, a fluorenyl group, a p-methoxyphenyl group, a tolylgroup, a xylyl group, a butylphenyl group, an octylphenyl group, and achlorophenyl group.

Specific examples of a thioalkyl group that may be used for Rx, Rz, orRy include a thiomethyl group, a thioethyl group, a thiopropyl group, athiobutyl group, a thiopentyl group, a thiohexyl group, athiocyclopentyl group, a thiocyclohexyl group

Alternatively, the lock 301 within the locked structure may have thefollowing structure:

where Ra is an alkyl group having a carbon number of 1 to 20, anaminoalkyl group having a carbon number of 1 to 20, an alkyloxy grouphaving a carbon number of 1 to 20, a hydroxyalkyl group having a carbonnumber of 1 to 20, a substituted or unsubstituted aryl group having acarbon number of 1 to 20, or a thioalkyl group having a carbon number of1 to 20. In this embodiment the aminoalkyl group, the alkyloxy group,the hydroxyalkyl group, the aryl group, and the thioalkyl group may besimilar to the groups discussed above with respect to the previous lock301. In more particular embodiments Ra may be an alkyloxy, anaminoalkyl, and a thioalkyl group, or the like.

In yet another embodiment the lock 301 within the locked structure mayhave the following structure:

where Rx is a hydrogen, halogen, an alkyl group having a carbon numberof 1 to 20, an aminoalkyl group having a carbon number of 1 to 20, analkyloxy group having a carbon number of 1 to 20, an aminoalkyl grouphaving a carbon number of 1 to 20 a hydroxyalkyl group having a carbonnumber of 1 to 20, a substituted or unsubstituted aryl group having acarbon number of 1 to 20, or a thioalkyl group having a carbon number of1 to 20 and where Ra is an alkyl group having a carbon number of 1 to20, an aminoalkyl group having a carbon number of 1 to 20, an alkyloxygroup having a carbon number of 1 to 20, a hydroxyalkyl group having acarbon number of 1 to 20, a substituted or unsubstituted aryl grouphaving a carbon number of 1 to 20, or a thioalkyl group having a carbonnumber of 1 to 20. In this embodiment the aminoalkyl group, the alkyloxygroup, the hydroxyalkyl group, the aryl group, and the thioalkyl groupmay be similar to the groups discussed above with respect to theprevious lock 301. In more particular embodiments Ra may be an alkyloxy,an aminoalkyl, and a thioalkyl group or the like.

The lock 301 as described above is incorporated into a ring structure toform the locked structure. In an embodiment the locked structurecomprises the lock 301 bonded in a ring with other units, such aschromophore units. In an embodiment the chromophore units are lightabsorbing units that absorb light at the wavelength which is used toexpose the photoresist 701. Such chromophore units include hydrocarbonaromatic moieties and heterocyclic aromatic moieties with from one tofour rings, either separated from each other or fused together, whereinthere are from three to ten carbons in each ring.

As one particular example of a locking monomer, the locking monomer mayhave the following structure:

wherein R, R1, and R2 may be the same or different and each representsan alkyl group having a carbon number of 1 to 20, an aminoalkyl grouphaving a carbon number of 1 to 20, a hydroxyalkyl group having a carbonnumber of 1 to 20 or a substituted or unsubstituted aryl group having acarbon number of 1 to 20.

In an embodiment a locked monomer is one monomer that repeats within thepolymer resin. However, while the locked monomer may be used by itselfto form the polymer resin, in other embodiments the polymer resin is acombination of the locked monomer and other monomers repeating togetherto form the polymer resin.

The other repeating resins may comprise a cross-linking monomer and amonomer with chromophore units, as described above with respect to thelocking monomer. In an embodiment the monomer with the chromophore unitmay comprise vinyl compounds containing substituted and unsubstitutedphenyl, substituted and unsubstituted anthracyl, substituted andunsubstituted phenanthryl, substituted and unsubstituted naphthyl,substituted and unsubstituted heterocyclic rings containing heteroatomssuch as oxygen, nitrogen, sulfur, or combinations thereof, such aspyrrolidinyl, pyranyl, piperidinyl, acridinyl, quinolinyl. Thesubstituents in these units may be any hydrocarbyl group and may furthercontain heteroatoms, such as, oxygen, nitrogen, sulfur or combinationsthereof, such as alkylenes, ester, ethers, combinations of these, or thelike, with a number of carbon atoms between 1 and 12.

In specific embodiments the monomers with chromophore units includestyrene, hydroxystyrene, acetoxystyrene, vinyl benzoate, vinyl4-tert-butylbenzoate, ethylene glycol phenyl ether acrylate,phenoxypropyl acrylate, N-methyl maleimide,2-(4-benzoyl-3-hydroxyphenoxy)ethyl acrylate, 2-hydroxy-3-phenoxypropylacrylate, phenyl methacrylate, benzyl methacrylate, 9-anthracenylmethylmethacrylate, 9-vinylanthracene, 2-vinylnaphthalene, N-vinylphthalimide,N-(3-hydroxy)phenyl methacrylamide,N-(3-hydroxy-4-hydroxycarbonylphenylazo)phenyl methacrylamide,N-(3-hydroxyl-4-ethoxycarbonylphenylazo)phenyl methacrylamide,N-(2,4-dinitrophenylamino phenyl)maleimide,3-(4-acetoaminophenyl)azo-4-hydroxystyrene,3-(4-ethoxycarbonylphenyl)azo-acetoacetoxy ethyl methacrylate,3-(4-hydroxyphenyl)azo-acetoacetoxy ethyl methacrylate,tetrahydroammonium sulfate salt of 3-(4-sulfophenyl)azoacetoacetoxyethyl methacrylate combinations of these, or the like. However, anysuitable monomer with chromophore units to absorb the impinging lightand prevent the light from being reflected may alternatively be used,and all such monomers are fully intended to be included within the scopeof the embodiments.

The cross-linking monomer may be used to cross-link the monomer withother polymers within the polymer resin modify the solubility of theBARC layer 105, and may optionally have an acid labile group. In aparticular embodiment the cross-linking monomer may comprise ahydrocarbon chain that also comprises, e.g., a hydroxyl group, acarboxyl acid group, a carboxylic ester group, epoxy groups, urethanegroups, amide groups, combinations of the, and the like. Specificexamples of cross-linking monomers that may be utilized includepolyhydroxystyrene, poly(hydroxynaphthalene), poly(metha)crylates,polyarylates, polyesters, polyurethanes, alkyd resins (aliphaticpolyesters), poly(hydroxystyrene-methylmethacrylate), homopolymersand/or copolymers obtained by polymerization of at least one of thefollowing monomers: styrene, hydroxystyrene, hydroxyethyl(meth)acrylate,hydroxypropyl(meth)acrylate, methyl(meth)acrylate, ethyl(meth)acrylate,(meth)acrylic acid, poly(hydroxystyrene-styrene-methacrylate),poly(hydroxystyrene-styrene-methacrylate), poly(4-hydroxystyrene), andpoly(pyromellitic dianhydride-ethylene glycol-propylene oxide).

Additionally, as one of ordinary skill in the art will recognize, theabove description for the various monomers that may be polymerized toform the polymer resin for the BARC layer 105 are intended to beillustrative and are not intended to limit the embodiments in anyfashion. Rather, any suitable monomer or combination of monomers thatperform the desired functions of the monomers described herein may alsobe utilized. All such monomers are fully intended to be included withinthe scope of the embodiments.

The catalyst may be a compound that is used to generate a chemicallyactive species and initiate a cross-linking reaction between thepolymers within the polymer resin and may be, e.g., thermal acidgenerator, a photoacid generator, or a photobase generator, suitablecombinations of these, or the like. In an embodiment in which thecatalyst is a thermal acid generator, the catalyst will generate an acidwhen sufficient heat is applied to the BARC layer 105. Specific examplesof the thermal acid generator include butane sulfonic acid, triflicacid, nanoflurobutane sulfonic acid, nitrobenzyl tosylates, such as2-nitrobenzyl tosylate, 2,4-dinitrobenzyl tosylate, 2,6-dinitrobenzyltosylate, 4-nitrobenzyl tosylate; benzenesulfonates such as2-trifluoromethyl-6-nitrobenzyl 4-chlorobenzenesulfonate,2-trifluoromethyl-6-nitrobenzyl 4-nitro benzenesulfonate; phenolicsulfonate esters such as phenyl, 4-methoxybenzenesulfonate; alkylammonium salts of organic acids, such as triethylammonium salt of10-camphorsulfonic acid, combinations of these, or the like.

In an embodiment in which the catalyst is a photoacid generator, thecatalyst may comprise halogenated triazines, onium salts, diazoniumsalts, aromatic diazonium salts, phosphonium salts, sulfonium salts,iodonium salts, imide sulfonate, oxime sulfonate, diazodisulfone,disulfone, o-nitrobenzylsulfonate, sulfonated esters, halogeneratedsulfonyloxy dicarboximides, diazodisulfones, α-cyanooxyamine-sulfonates,imidesulfonates, ketodiazosulfones, sulfonyldiazoesters,1,2-di(arylsulfonyl)hydrazines, nitrobenzyl esters, and the s-triazinederivatives, suitable combinations of these, and the like.

Specific examples of photoacid generators that may be used includeα-(trifluoromethylsulfonyloxy)-bicyclo[2.2.1]hept-5-ene-2,3-dicarbo-ximide(MDT), N-hydroxy-naphthalimide (DDSN), benzoin tosylate,t-butylphenyl-α-(p-toluenesulfonyloxy)-acetate andt-butyl-α-(p-toluenesulfonyloxy)-acetate, triarylsulfonium anddiaryliodonium hexafluoroantimonates, hexafluoroarsenates,trifluoromethanesulfonates, iodonium perfluorooctanesulfonate,N-camphorsulfonyloxynaphthalimide,N-pentafluorophenylsulfonyloxynaphthalimide, ionic iodonium sulfonatessuch as diaryl iodonium (alkyl or aryl) sulfonate andbis-(di-t-butylphenyl)iodonium camphanylsulfonate,perfluoroalkanesulfonates such as perfluoropentanesulfonate,perfluorooctanesulfonate, perfluoromethanesulfonate, aryl (e.g., phenylor benzyl) triflates such as triphenylsulfonium triflate orbis-(t-butylphenyl)iodonium triflate; pyrogallol derivatives (e.g.,trimesylate of pyrogallol), trifluoromethanesulfonate esters ofhydroxyimides, a,&-bis-sulfonyl-diazomethanes, sulfonate esters ofnitro-substituted benzyl alcohols, naphthoquinone-4-diazides, alkyldisulfones, and the like.

In other embodiment the catalyst may be a photobase generator. In suchan embodiment the photobase generator may comprise quaternary ammoniumdithiocarbamates, a aminoketones, oxime-urethane containing moleculessuch as dibenzophenoneoxime hexamethylene diurethan, ammoniumtetraorganylborate salts, and N-(2-nitrobenzyloxycarbonyl) cyclicamines, suitable combinations of these, or the like.

The cross-linking agent may also be added to the BARC layer 105. Thecross-linking agent reacts with the polymers within the polymer resinwithin the BARC layer 105 after exposure, assisting in increasing thecross-linking density of the photoresist, which helps to improve theresist pattern and resistance to dry etching. In an embodiment thecross-linking agent may be an melamine based agent, a urea based agent,ethylene urea based agent, propylene urea based agent, glycoluril basedagent, an aliphatic cyclic hydrocarbon having a hydroxyl group, ahydroxyalkyl group, or a combination of these, oxygen containingderivatives of the aliphatic cyclic hydrocarbon, glycoluril compounds,etherified amino resins, a polyether polyol, a polyglycidil ether, avinyl ether, a triazine, combinations of these, or the like.

Specific examples of materials that may be utilized as a cross-linkingagent include melamine, acetoguanamine, benzoguanamine, urea, ethyleneurea, or glycoluril with formaldehyde, glycoluril with a combination offormaldehyde and a lower alcohol, hexamethoxymethylmelamine,bismethoxymethylurea, bismethoxymethylbismethoxyethylene urea,tetramethoxymethylglycoluril, and tetrabutoxymethylglycoluril, mono-,di-, tri-, or tetra-hydroxymethylated glycoluril, mono-, di-, tri-,and/or tetra-methoxymethylated glycoluril, mono-, di-, tri-, and/ortetra-ethoxymethylated glycoluril, mono-, di-, tri-, and/ortetra-propoxymethylated glycoluril, and mono-, di-, tri-, and/ortetra-butoxymethylated glycoluril,2,3-dihydroxy-5-hydroxymethylnorbornane,2-hydroy-5,6-bis(hydroxymethyl)norbornane, cyclohexanedimethanol,3,4,8(or 9)-trihydroxytricyclodecane, 2-methyl-2-adamantanol,1,4-dioxane-2,3-diol and 1,3,5-trihydroxycyclohexane, tetramethoxymethylglycoluril, methylpropyltetramethoxymethyl glycoluril, andmethylphenyltetramethoxymethylglycoluril,2,6-bis(hydroxymethyl)p-cresol, N-methoxymethyl- orN-butoxymethyl-melamine. Additionally, compounds obtained by reactingformaldehyde, or formaldehyde and lower alcohols with aminogroup-containing compounds, such as melamine, acetoguanamine,benzoguanamine, urea, ethylene urea and glycoluril, and substituting thehydrogen atoms of the amino group with hydroxymethyl group or loweralkoxymethyl group, examples being hexamethoxymethylmelamine,bismethoxymethyl urea, bismethoxymethylbismethoxyethylene urea,tetramethoxymethyl glycoluril and tetrabutoxymethyl glycoluril,copolymers of 3-chloro-2-hydroxypropyl methacrylate and methacrylicacid, copolymers of 3-chloro-2-hydroxypropyl methacrylate and cyclohexylmethacrylate and methacrylic acid, copolymers of3-chloro-2-hydroxypropyl methacrylate and benzyl methacrylate andmethacrylic acid, bisphenol A-di(3-chloro-2-hydroxypropyl)ether,poly(3-chloro-2-hydroxypro-pyl)ether of a phenol novolak resin,pentaerythritol tetra(3-chloro-2-hydroxypropyl)ether, trimethylolmethanetri(3-chloro-2-hydroxypropyl)ether phenol, bisphenolA-di(3-acetoxy-2-hydroxypropyl)ether,poly(3-acetoxy-2-hydroxypropyl)ethe-r of a phenol novolak resin,pentaerythritol tetra(3-acetoxy-2-hydroxyprop-yl)ether, pentaerythritolpoly(3-chloroacetoxy-2-hydroxypropyl)ether, trimethylolmethanetri(3-acetoxy-2-hydroxypropyl)ether, combinations of these, or the like.

Additionally, as one of ordinary skill in the art will recognize, theprecise examples listed above regarding the structures and groups thatmay be used within the polymer resin, the catalyst, and thecross-linking agent are merely intended to be illustrative and are notintended to list every possible structure or groups that may be utilizedto form the polymer resin, the catalyst, and the cross-linking agent.Any suitable alternative structures and any suitable alternative groupsmay be used to form the polymer resin, the catalyst, and thecross-linking agent, and all such structures and groups are fullyintended to be included within the scope of the embodiments.

The individual components of the BARC layer 105 may be placed into theBARC solvent in order to aid in the mixing and placement of the BARClayer 105. To aid in the mixing and placement of the BARC layer 105, thesolvent is chosen at least in part based upon the materials and monomerschosen for the polymer resin of the BARC layer 105 as well as thecatalyst and the cross-linking agent. In particular, the BARC solvent ischosen such that the polymer resin, the catalyst, and the cross-linkingagent can be evenly dissolved into the BARC solvent and dispensed uponthe substrate 101 and the fins 103.

In an embodiment the BARC solvent may be an organic solvent, and maycomprise any suitable solvent such as ketones, alcohols, polyalcohols,ethers, glycol ethers, cyclic ethers, aromatic hydrocarbons, esters,propionates, lactates, lactic esters, alkylene glycol monoalkyl ethers,alkyl lactates, alkyl alkoxypropionates, cyclic lactones, monoketonecompounds that contain a ring, alkylene carbonates, alkyl alkoxyacetate,alkyl pyruvates, lactate esters, ethylene glycol alkyl ether acetates,diethylene glycols, propylene glycol alkyl ether acetates, alkyleneglycol alkyl ether esters, alkylene glycol monoalkyl esters, or thelike.

Specific examples of materials that may be used as the BARC solventinclude, acetone, methanol, ethanol, toluene, xylene,4-hydroxy-4-methyl-2-pentatone, tetrahydrofuran, methyl ethyl ketone,cyclohexanone, methyl isoamyl ketone, 2-heptanone, ethylene glycol,ethylene glycol monoacetate, ethylene glycol dimethyl ether, ethyleneglycol dimethyl ether, ethylene glycol methylethyl ether, ethyleneglycol monoetheryl ether, methyl celluslve acetate, ethyl cellosolveacetate, diethylene glycol, diethylene glycol monoacetate, diethyleneglycol monomethyl ether, diethylene glycol diethyl ether, diethyleneglycol dimethyl ether, diethylene glycol ethylmethyl ether, dietheryleneglycol monoethyl ether, diethylene glycol monbutyl ether, ethyl2-hydroxypropionate, methyl 2-hydroxy-2-methylpropionate, ethyl2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate,methyl 2-hydroxy-2-methylbutanate, methyl 3-methoxypropionate, ethyl3-methoxypropionate, methyl 3-ethoxypropionate, ethyl3-ethoxypropionate, ethyl acetate, butyl acetate, methyl lactate andethyl lactate, propylene glycol, propylene glycol monoacetate, propyleneglycol monoethyl ether acetate, propylene glycol monomethyl etheracetate, propylene glycol monopropyl methyl ether acetate, propyleneglycol monobutyl ether acetate, propylene glycol monobutyl etheracetate, propylene glycol monomethyl ether propionate, propylene glycolmonoethyl ether propionate, proplyelen glycol methyl ether adcetate,proplylene glycol ethyl ether acetate, ethylene glycol monomethyl etheracetate, ethylene glycol monoethyl ether acetate, propylene glycolmonomethyl ether, propylene glycol monoethyl ether, propylene glycolmonopropyl ether, propylene glycol monobutyl ether, ethylene glycolmonomethyl ether, ethylene glycol monoethyl ether, methyl lactate, ethyllactate, propyl lactate, and butyl lactate, ethyl 3-ethoxypropionate,methyl 3-methoxypropionate, methyl 3-ethoxypropionate, and ethyl3-methoxypropionate, β-propiolactone, β-butyrolactone, γ-butyrolactone,α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ-valerolactone,γ-caprolactone, γ-octanoic lactone, α-hydroxy-γ-butyrolactone,2-butanone, 3-methylbutanone, pinacolone, 2-pentanone, 3-pentanone,4-methyl-2-pentanone, 2-methyl-3-pentanone, 4,4-dimethyl-2-pentanone,2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone, 2-hexanone,3-hexanone, 5-methyl-3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone,2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4-heptanone,2-octanone, 3-octanone, 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone,3-decanone, 4-decanone, 5-hexene-2-one, 3-pentene-2-one, cyclopentanone,2-methylcyclopentanone, 3-methylcyclopentanone,2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopentanone,cyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone,4-ethylcyclohexanone, 2,2-dimethylcyclohexanone,2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone,2-methylcycloheptanone, 3-methylcycloheptanone, pylene carbonate,vinylene carbonate, ethylene carbonate, and butylene carbonate,acetate-2-methoxyethyl, acetate-2-ethoxyethyl,acetate-2-(2-ethoxyethoxy)ethyl, acetate-3-methoxy-3-methylbutyl,acetate-1-methoxy-2-propyl, dipropylene glycol, monomethylether,monoethylether, monopropylether, monobutylehter, monopheylether,dipropylene glycol monoacetate, dioxane, methyl lactate, etheyl lactate,methyl acetate, ethyl acetate, butyl acetate, methyl puruvate, ethylpuruvate, propyl pyruvate, methyl methoxypropionate, ethylethoxypropionate, n-methylpyrrolidone (NMP), 2-methoxyethyl ether(diglyme), ethylene glycol monom-ethyl ether, propylene glycolmonomethyl ether; ethyl lactate or methyl lactate, methyl proponiate,ethyl proponiate and ethyl ethoxy proponiate, methylethyl ketone,cyclohexanone, 2-heptanone, carbon dioxide, cyclopentatone,cyclohexanone, ethyl 3-ethocypropionate, ethyl lactate, propylene glycolmethyl ether acetate (PGMEA), methylene cellosolve, butyle acetate, and2-ethoxyethanol, N-methylformamide, N,N-dimethylformamide,N-methylformanilide, N-methylacetamide, N,N-dimethylacetamide,N-methylpyrrolidone, dimethylsulfoxide, benzyl ethyl ether, dihexylether, acetonylacetone, isophorone, caproic acid, caprylic acid,1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate,diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate,propylene carbonate, phenyl cellosolve acetate, or the like.

However, as one of ordinary skill in the art will recognize, thematerials listed and described above as examples of materials that maybe utilized for the solvent component of the BARC layer 105 are merelyillustrative and are not intended to limit the embodiments. Rather, anysuitable material that may dissolve the polymer resin, the catalyst, andthe cross-linking agent may alternatively be utilized to help mix andapply the BARC layer 105. All such materials are fully intended to beincluded within the scope of the embodiments.

Additionally, other components may also be added into the material forthe BARC layer 105 if desired. For example, in an embodiment themonomeric dyes, surface leveling agents, adhesion promoters,anti-foaming agent, and the like, may alternatively be utilized. Anysuitable additive may be added into the material for the BARC layer 105,and all such additives are fully intended to be included within thescope of the embodiments.

In an embodiment the polymer resins (comprising the locked monomer), thecatalyst, and the cross-linking agent, along with any desired additivesor other agents, are added to the BARC solvent to form the material forthe BARC layer 105. The polymer resins may have a concentration ofbetween about 0.1% and about 30%, such as about 10%, the catalyst mayhave a concentration of between about 0.1% and about 30%, such as about5%, and the cross-linking agent may have a concentration of betweenabout 10% and about 20%, such as about 5%.

Once added, the mixture is then mixed in order to achieve an even andconstant composition throughout the material for the BARC layer 105 inorder to ensure that there are no defects caused by an uneven mixing ornon-constant composition of the material for the BARC layer 105. Oncemixed together, the material for the BARC layer 105 may either be storedprior to its usage or else used immediately.

Once the material for the BARC layer 105 has been prepared, the materialfor the BARC layer 105 may be utilized by initially applying thematerial for the BARC layer 105 onto the substrate 101 and the fins 103.The material for the BARC layer 105 may be applied to the substrate 101and the fins 103 so that the material for the BARC layer 105 coats anupper exposed surface of the substrate 101 and the fins 103, and may beapplied using a process such as a spin-on coating process, a dip coatingmethod, an air-knife coating method, a curtain coating method, awire-bar coating method, a gravure coating method, a lamination method,an extrusion coating method, combinations of these, or the like. In anembodiment the material for the BARC layer 105 may be applied such thatit has a thickness over a top of the fins 103 of between about 50 nm andabout 500 nm, such as about 300 nm.

FIG. 2 illustrates a pre-bake of the BARC layer 105 (represented in FIG.2 by the wavy lines labeled 201) and its resulting consequences. In anembodiment once the BARC layer 105 has been applied to the substrate 101and the fins 103, the pre-bake 201 of the BARC layer 105 is performed inorder to initiate a cross-linking reaction between the polymers withinthe polymer resin and the cross-linking agent as well as to dry the BARClayer 105 prior to the application of the photoresist 701. The curingand drying of the BARC layer 105 removes a portion of the BARC solventcomponents but leaves behind the polymers, the catalysts, thecross-linking agent, and other additives. In an embodiment the pre-bake201 may be performed at a temperature suitable to evaporate the BARCsolvent and initiate the cross-linking reaction, such as between about40° C. and 150° C., although the precise temperature depends upon thematerials chosen for the BARC layer 105. The pre-bake 201 is performedfor a time sufficient to cure and dry the BARC layer 105, such asbetween about 10 seconds to about 5 minutes, such as about 90 seconds.

However, the pre-bake 201 of the BARC layer 105 also has a number ofnegative consequences. In particular, because the BARC layer 105 coversan uneven surface of surfaces (including the surface of the substrate101 as well as the fins 103 extending from the surface of the substrate101), there is an uneven distribution of heat transfer through the BARClayer 105 during the pre-bake 201. For example, in a region in which theBARC layer 105 covers the fins 103, the heat applied to the BARC layer105 in this region will transfer into the BARC solvent (which will helpto drive off the BARC solvent) but will also transfer into the fins 103,thereby removing heat from the BARC solvent. However, in regions wherethe fins 103 are not located (and so cannot remove heat from the BARCsolvent), the heat will transfer into the BARC solvent and be used forvaporization of the BARC solvent.

As such, because one section of the BARC solvent (the section over thefins 103) has heat being removed from it while another section (thesection not over the fins 103) does not, the BARC solvent does notvaporize evenly out of the BARC layer 105. In particular, in the areaswhere no fins 103 are located to remove heat the BARC solvent mayvaporize at a faster rate than sections of the BARC solvent that arelocated over regions that do include the fins 103. As such, more of theBARC solvent will be vaporized in one region than in another, causing athickness in one region to be thinner than in the other region. In aparticular embodiment, the difference in heights may be a first distanceD₁ such as greater than about 50 nm.

Additionally, in embodiments in which the catalyst is a thermal acidgenerator, the pre-bake 201 will induce the catalyst to generate acid,which will then initiate cross-linking reactions within the BARC layer105. For example, the acids can induce the cross-linking agent to startreacting with the polymers within the polymer resin to produce thecross-linked polymers. One such cross-linking reaction may berepresented by the following chemical formula:

C₁—OH+MeO—P₁→P₁—O—P₂+MeOH

where C1 is a cross-linking agent with an OH group and P1 is a polymercomprising an MeO group. As can be seen, when the cross-linking agentreacts with the polymers within the polymer resin, the cross-linkingagent forms the cross-linked polymers, but also drives off a MeOH as aby-product. This by-product (and other reaction by-products that may beformed) will vaporize within the BARC layer 105 itself (not necessarilyat its surface) and will causing voids (represented in FIG. 2 by thecircle labeled 207) to occur within the BARC layer 105. These voids 207may lead to undesirable process defects during later processing.

FIGS. 3A-3B illustrate one embodiment in which the differences in heightand the voids 207 may be reduced or eliminated by unlocking the lockedstructure within the locked monomer of the BARC layer 105. In anembodiment the lock 301 within the locked structure may be cleaved in ahydrolysis reaction initiated by, e.g., an acid generated by thecatalyst during the pre-bake 201. For example, in an embodiment in whichthe catalyst is a thermal acid generator, the thermal acid generatorwill form an acid (e.g., a H⁺ atom) during the pre-bake 201. The acidwill break the bonds within the lock 301, cleaving the lock 301 andallowing the locked structure to expand.

FIG. 3A illustrates a molecular chemical reaction of one particularembodiment of a locked monomer being cleaved by an acid generated by thecatalyst. As illustrated, the acid (e.g., the H⁺ atom labeled 303) willreact with the chemical bonds in the lock 301 (represented in FIG. 3A bythe dashed line 301), and particularly the bond between the carbon atomand the single bonded oxygen atom in the carboxyl group of the lock 301.This reaction will break the bond within the lock 301, thereby cleavingthe lock 301 within the locked structure.

Once the lock 301 has been cleaved and unlocked, there is no longer abond forcing the cyclic structure to remain in such a tight, cyclicform. As such, once the lock 301 has been cleaved the other bonds andforces within the previously locked structure will pull the lockedstructure out of its previous cyclic form. As a result, the previouslylocked structure will transform from a cyclic structure to a more linearform (although the precise structural shape will be determined by theatomic makeup of the now unlocked structure).

Such a reshaping of the locked structure from a more cyclic to a morelinear form also means that the now unlocked monomer will have anincreased length and take up more space and volume than the lockedmonomer did prior to the lock 301 being cleaved. As such, with each ofthe locked monomers in the polymers now being unlocked, the overalldensity of the polymer resin will be decrease. As such, because one ofthe components of the BARC layer 105 is decreasing in density, theoverall density of the BARC layer 105 itself will decrease, causing theBARC layer 105 to take up more space and essentially becomeself-expanding.

FIG. 3B illustrates a result of this self-expansion of the BARC layer105. In particular, as the locked monomers are unlocked and the BARClayer 105 expands, the differences in thickness in the BARC layer 105will be reduced or eliminated. In particular the BARC layer 105 willexpand away from its original position after the pre-bake 201(illustrated in FIG. 3B by the dashed line labeled 307). Additionally,as the BARC layer 105 expands, the voids 107 that were previously formedwithin the BARC layer 105 may be eliminated by the expanding materialexpanding into the voids 107 or reduced in size so as to minimize theireffect on later processing.

FIG. 4 illustrates one embodiment in which the catalyst may initiate theunlocking of the locked monomers using an exposure process. In anembodiment the exposure may be initiated by placing the substrate 101and the BARC layer 105, once cured and dried, into an imaging device 400for exposure. The imaging device 400 may comprise a support plate 405,an energy source 407, and optics 413. In an embodiment the support plate405 is a surface to which the semiconductor device 100 and the BARClayer 105 may be placed or attached to and which provides support andcontrol to the substrate 101 during exposure of the BARC layer 105.Additionally, the support plate 405 may be movable along one or moreaxes, as well as providing any desired heating or cooling to thesubstrate 101 and BARC layer 105 in order to prevent temperaturegradients from affecting the exposure process.

In an embodiment the energy source 407 supplies energy 411 such as lightto the BARC layer 105 in order to induce a reaction of the photoacidgenerators, which in turn reacts with the locks in the locked monomersto unlock the locked monomers. In an embodiment the energy 411 may beelectromagnetic radiation, such as g-rays (with a wavelength of about436 nm), i-rays (with a wavelength of about 365 nm), ultravioletradiation, far ultraviolet radiation, x-rays, electron beams, or thelike. The energy source 407 may be a source of the electromagneticradiation, and may be a KrF excimer laser light (with a wavelength of248 nm), an ArF excimer laser light (with a wavelength of 193 nm), a F₂excimer laser light (with a wavelength of 157 nm), or the like, althoughany other suitable source of energy 411, such as mercury vapor lamps,xenon lamps, carbon arc lamps or the like, may alternatively beutilized.

Optics (represented in FIG. 4 by the trapezoid labeled 413) may be usedto concentrate, expand, reflect, or otherwise control the energy 411 asit leaves the energy source 407 and is directed towards the BARC layer105. In an embodiment the optics 413 comprise one or more lenses,mirrors, filters, combinations of these, or the like to control theenergy 411 along its path.

In an embodiment the semiconductor device 100 with the BARC layer 105 isplaced on the support plate 405. Once the BARC layer 105 is in position,the energy source 407 generates the desired energy 411 (e.g., light)which passes through the optics 413 on its way to the BARC layer 105.The energy 411 impinges upon the BARC layer 105 and induces a reactionof the photoacid generators within the BARC layer 105. The chemicalreaction products of the photoacid generators absorption of the energy411 (e.g., acids/bases/free radicals) then reacts with the locks withinthe locked monomers of the polymer resin, unlocking the locks andcausing the BARC layer 105 to expand.

FIG. 5 illustrates one possible chemical reaction mechanism in anembodiment in which the catalyst is a photobase generator and theunlocking is performed using an exposure process similar to the onedescribed above with respect to FIG. 4. In this embodiment, rather thanthe catalyst generating an acid, the catalyst, upon absorbing theimpinging light from the exposure process, will generate a base(represented in FIG. 5 by the number 501), such as amine. This base 501will then cleave the lock 301 within the locked monomer, unlocking thelocked monomer and allowing the cyclic locked monomer to expand to amore linear shape, thereby decreasing the density of the BARC layer 105in general and causing the BARC layer 105 to self-expand.

FIG. 6 illustrates yet another embodiment that may be used to unlock thelocked monomer in which the catalyst is a thermal acid generator. Inthis embodiment an unlocking bake process (represented in FIG. 6 by thewavy lines labeled 601) is utilized to activate the thermal acidgenerator and generate an acid. In an embodiment the BARC layer 105 isheated to a temperature such that the thermal acid generator willgenerate an acid (e.g., a H⁺ atom). Once generated, the acid will cleavethe lock 301 within the locked monomer as described above with respectto FIG. 3A, and the BARC layer 105 will self-expand.

In a particular embodiment the unlocking bake 601 may be performed byplacing the substrate 101 and overlying BARC layer 105 onto, e.g., ahot-plate (not individually illustrated) with heating elements inside ofthe hot-plate, although any suitable heating device (such as a furnace)may alternatively be used. The heating elements may then be engaged toheat the hot-plate and, thus, heat the substrate 101 and the BARC layer105. In an embodiment the BARC layer 105 may be heated to a temperatureof between about 100° C. and about 350° C., such as about 250° C.

In yet another embodiment the two-step baking process described abovewith respect to FIGS. 1-6 (e.g., the original pre-bake 201 to drive offsolvent described with respect to FIG. 2 and the unlocking bake 601described with respect to FIG. 6), may be replaced with a single bake toperform the cross-linking as well as to perform the unlocking of thelocked monomers. In an embodiment the single bake may be performed at atemperature of between about 100° C. and about 350° C., such as about250° C. By performing the single bake at this temperature, the thermalacid generator will generate enough acid to initiate the cross-linkingwhile also generating enough acid to cleave the locks on the lockedmonomers. As such, the BARC layer 105 will cure and unlock in a singlestep, resulting in process efficiencies.

FIGS. 7A-7B illustrates an application, exposure, and development of aphotoresist 701 over the BARC layer 105. In an embodiment thephotoresist 701 includes a photoresist polymer resin along with one ormore photoactive compounds (PACs) in a photoresist solvent. In anembodiment the photoresist polymer resin may comprise a hydrocarbonstructure (such as a alicyclic hydrocarbon structure) that contains oneor more groups that will decompose (e.g., acid labile groups) orotherwise react when mixed with acids, bases, or free radicals generatedby the PACs (as further described below). In an embodiment thehydrocarbon structure comprises a repeating unit that forms a skeletalbackbone of the photoresist polymer resin. This repeating unit mayinclude acrylic esters, methacrylic esters, crotonic esters, vinylesters, maleic diesters, fumaric diesters, itaconic diesters,(meth)acrylonitrile, (meth)acrylamides, styrenes, vinyl ethers,combinations of these, or the like.

Specific structures which may be utilized for the repeating unit of thehydrocarbon structure include methyl acrylate, ethyl acrylate, n-propylacrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate,tert-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate,acetoxyethyl acrylate, phenyl acrylate, 2-hydroxyethyl acrylate,2-methoxyethyl acrylate, 2-ethoxyethyl acrylate,2-(2-methoxyethoxy)ethyl acrylate, cyclohexyl acrylate, benzyl acrylate,2-alkyl-2-adamantyl(meth)acrylate ordialkyl(1-adamantyl)methyl(meth)acrylate, methyl methacrylate, ethylmethacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butylmethacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-hexylmethacrylate, 2-ethylhexyl methacrylate, acetoxyethyl methacrylate,phenyl methacrylate, 2-hydroxyethyl methacrylate, 2-methoxyethylmethacrylate, 2-ethoxyethyl methacrylate, 2-(2-methoxyethoxy)ethylmethacrylate, cyclohexyl methacrylate, benzyl methacrylate,3-chloro-2-hydroxypropyl methacrylate, 3-acetoxy-2-hydroxypropylmethacrylate, 3-chloroacetoxy-2-hydroxypropyl methacrylate, butylcrotonate, hexyl crotonate and the like. Examples of the vinyl estersinclude vinyl acetate, vinyl propionate, vinyl butylate, vinylmethoxyacetate, vinyl benzoate, dimethyl maleate, diethyl maleate,dibutyl maleate, dimethyl fumarate, diethyl fumarate, dibutyl fumarate,dimethyl itaconate, diethyl itaconate, dibutyl itaconate, acrylamide,methyl acrylamide, ethyl acrylamide, propyl acrylamide, n-butylacrylamide, tert-butyl acrylamide, cyclohexyl acrylamide, 2-methoxyethylacrylamide, dimethyl acrylamide, diethyl acrylamide, phenyl acrylamide,benzyl acrylamide, methacrylamide, methyl methacrylamide, ethylmethacrylamide, propyl methacrylamide, n-butyl methacrylamide,tert-butyl methacrylamide, cyclohexyl methacrylamide, 2-methoxyethylmethacrylamide, dimethyl methacrylamide, diethyl methacrylamide, phenylmethacrylamide, benzyl methacrylamide, methyl vinyl ether, butyl vinylether, hexyl vinyl ether, methoxyethyl vinyl ether, dimethylaminoethylvinyl ether and the like. Examples of the styrenes include styrene,methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene,isopropyl styrene, butyl styrene, methoxy styrene, butoxy styrene,acetoxy styrene, chloro styrene, dichloro styrene, bromo styrene, vinylmethyl benzoate, α-methyl styrene, maleimide, vinylpyridine,vinylpyrrolidone, vinylcarbazole, combinations of these, or the like.

In an embodiment the repeating unit of the hydrocarbon structure mayalso have either a monocyclic or a polycyclic hydrocarbon structuresubstituted into it, or else the monocyclic or polycyclic hydrocarbonstructure may be the repeating unit, in order to form an alicyclichydrocarbon structure. Specific examples of monocyclic structures thatmay be used include bicycloalkane, tricycloalkane, tetracycloalkane,cyclopentane, cyclohexane, or the like. Specific examples of polycyclicstructures that may be used include adamantine, norbornane, isobornane,tricyclodecane, tetracycododecane, or the like.

The group which will decompose, otherwise known as a leaving group or,in an embodiment in which the PAC is a photoacid generator, an acidlabile group, is attached to the hydrocarbon structure so that it willreact with the acids/bases/free radicals generated by the PACs duringexposure. In an embodiment the group which will decompose may be acarboxylic acid group, a fluorinated alcohol group, a phenolic alcoholgroup, a sulfonic group, a sulfonamide group, a sulfonylimido group, an(alkylsulfonyl) (alkylcarbonyl)methylene group, an(alkylsulfonyl)(alkyl-carbonyl)imido group, abis(alkylcarbonyl)methylene gourp, a bis(alkylcarbonyl)imido group, abis(alkylsylfonyl)methylene group, a bis(alkylsulfonyl)imido group, atris(alkylcarbonyl methylene group, a tris(alkylsulfonyl)methylenegroup, combinations of these, or the like. Specific groups that may beutilized for the fluorinated alcohol group include fluorinatedhydroxyalkyl groups, such as a hexafluoroisopropanol group. Specificgroups that may be utilized for the carboxylic acid group includeacrylic acid groups, methacrylic acid groups, or the like.

In an embodiment the photoresist polymer resin may also comprise othergroups attached to the hydrocarbon structure that help to improve avariety of properties of the polymerizable resin. For example, inclusionof a lactone group to the hydrocarbon structure assists to reduce theamount of line edge roughness after the photoresist 701 has beendeveloped, thereby helping to reduce the number of defects that occurduring development. In an embodiment the lactone groups may includerings having five to seven members, although any suitable lactonestructure may alternatively be used for the lactone group.

The photoresist polymer resin may also comprise groups that can assistin increasing the adhesiveness of the photoresist 701 to underlyingstructures (e.g., the BARC layer 105). In an embodiment polar groups maybe used to help increase the adhesiveness, and polar groups that may beused in this embodiment include hydroxyl groups, cyano groups, or thelike, although any suitable polar group may alternatively be utilized.

Optionally, the photoresist polymer resin may further comprise one ormore alicyclic hydrocarbon structures that do not also contain a groupwhich will decompose. In an embodiment the hydrocarbon structure thatdoes not contain a group which will decompose may include structuressuch as 1-adamantyl(meth)acrylate, tricyclodecanyl(meth)acrylate,cyclohexayl(methacrylate), combinations of these, or the like.

Additionally, the photoresist 701 also comprises one or more PACs. ThePACs may be photoactive components such as photoacid generators,photobase generators, free-radical generators, or the like, and the PACsmay be positive-acting or negative-acting. In an embodiment in which thePACs are a photoacid generator, the PACs may comprise halogenatedtriazines, onium salts, diazonium salts, aromatic diazonium salts,phosphonium salts, sulfonium salts, iodonium salts, imide sulfonate,oxime sulfonate, diazodisulfone, disulfone, o-nitrobenzylsulfonate,sulfonated esters, halogenerated sulfonyloxy dicarboximides,diazodisulfones, α-cyanooxyamine-sulfonates, imidesulfonates,ketodiazosulfones, sulfonyldiazoesters, 1,2-di(arylsulfonyl)hydrazines,nitrobenzyl esters, and the s-triazine derivatives, suitablecombinations of these, and the like.

Specific examples of photoacid generators that may be used includeα-(trifluoromethylsulfonyloxy)-bicyclo[2.2.1]hept-5-ene-2,3-dicarbo-ximide(MDT), N-hydroxy-naphthalimide (DDSN), benzoin tosylate,t-butylphenyl-α-(p-toluenesulfonyloxy)-acetate andt-butyl-α-(p-toluenesulfonyloxy)-acetate, triarylsulfonium anddiaryliodonium hexafluoroantimonates, hexafluoroarsenates,trifluoromethanesulfonates, iodonium perfluorooctanesulfonate,N-camphorsulfonyloxynaphthalimide,N-pentafluorophenylsulfonyloxynaphthalimide, ionic iodonium sulfonatessuch as diaryl iodonium (alkyl or aryl) sulfonate andbis-(di-t-butylphenyl)iodonium camphanylsulfonate,perfluoroalkanesulfonates such as perfluoropentanesulfonate,perfluorooctanesulfonate, perfluoromethanesulfonate, aryl (e.g., phenylor benzyl) triflates such as triphenylsulfonium triflate orbis-(t-butylphenyl)iodonium triflate; pyrogallol derivatives (e.g.,trimesylate of pyrogallol), trifluoromethanesulfonate esters ofhydroxyimides, α,α′-bis-sulfonyl-diazomethanes, sulfonate esters ofnitro-substituted benzyl alcohols, naphthoquinone-4-diazides, alkyldisulfones, and the like.

In an embodiment in which the PACs are a free-radical generator, thePACs may comprise n-phenylglycine, aromatic ketones such asbenzophenone, N,N-tetramethyl-4,4′-diaminobenzophenone,N,N′-tetraethyl-4,4′-diaminobenzophenone,4-methoxy-4′-dimethylaminobenzo-phenone,3,3′-dimethyl-4-methoxybenzophenone,p,p′-bis(dimethylamino)benzo-phenone,p,p′-bis(diethylamino)-benzophenone, anthraquinone,2-ethylanthraquinone, naphthaquinone and phenanthraquinone, benzoinssuch as benzoin, benzoinmethylether, benzoinethylether,benzoinisopropylether, benzoin-n-butylether, benzoin-phenylether,methylbenzoin and ethybenzoin, benzyl derivatives such as dibenzyl,benzyldiphenyldisulfide and benzyldimethylketal, acridine derivativessuch as 9-phenylacridine and 1,7-bis(9-acridinyl)heptane, thioxanthonessuch as 2-chlorothioxanthone, 2-methylthioxanthone,2,4-diethylthioxanthone, 2,4-dimethylthioxanthone and2-isopropylthioxanthone, acetophenones such as 1,1-dichloroacetophenone,p-t-butyldichloro-acetophenone, 2,2-diethoxyacetophenone,2,2-dimethoxy-2-phenylacetophenone, and2,2-dichloro-4-phenoxyacetophenone, 2,4,5-triarylimidazole dimers suchas 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer,2-(o-chlorophenyl)-4,5-di-(m-methoxyphenyl imidazole dimer,2-(o-fluorophenyl)-4,5-diphenylimidazole dimer,2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer,2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer,2,4-di(p-methoxyphenyl)-5-phenylimidazole dimer,2-(2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer and2-(p-methylmercaptophenyl)-4,5-diphenylimidazole dimmer, suitablecombinations of these, or the like.

In an embodiment in which the PACs are a photobase generator, the PACsmay comprise quaternary ammonium dithiocarbamates, a aminoketones,oxime-urethane containing molecules such as dibenzophenoneoximehexamethylene diurethan, ammonium tetraorganylborate salts, andN-(2-nitrobenzyloxycarbonyl) cyclic amines, suitable combinations ofthese, or the like. However, as one of ordinary skill in the art willrecognize, the chemical compounds listed herein are merely intended asillustrated examples of the PACs and are not intended to limit theembodiments to only those PACs specifically described. Rather, anysuitable PAC may alternatively be utilized, and all such PACs are fullyintended to be included within the scope of the present embodiments.

The individual components of the photoresist 701 may be placed into aphotoresist solvent in order to aid in the mixing and placement of thephotoresist 701. To aid in the mixing and placement of the photoresist701, the photoresist solvent is chosen at least in part based upon thematerials chosen for the photoresist polymer resin as well as the PACs.In particular, the photoresist solvent is chosen such that thephotoresist polymer resin and the PACs can be evenly dissolved into thephotoresist solvent and dispensed upon the BARC layer 105.

In an embodiment the photoresist solvent may be an organic solvent, andmay comprise any suitable solvent such as ketones, alcohols,polyalcohols, ethers, glycol ethers, cyclic ethers, aromatichydrocarbons, esters, propionates, lactates, lactic esters, alkyleneglycol monoalkyl ethers, alkyl lactates, alkyl alkoxypropionates, cycliclactones, monoketone compounds that contain a ring, alkylene carbonates,alkyl alkoxyacetate, alkyl pyruvates, lactate esters, ethylene glycolalkyl ether acetates, diethylene glycols, propylene glycol alkyl etheracetates, alkylene glycol alkyl ether esters, alkylene glycol monoalkylesters, or the like.

Specific examples of materials that may be used as the photoresistsolvent for the photoresist 701 include, acetone, methanol, ethanol,toluene, xylene, 4-hydroxy-4-methyl-2-pentatone, tetrahydrofuran, methylethyl ketone, cyclohexanone, methyl isoamyl ketone, 2-heptanone,ethylene glycol, ethylene glycol monoacetate, ethylene glycol dimethylether, ethylene glycol dimethyl ether, ethylene glycol methylethylether, ethylene glycol monoetheryl ether, methyl celluslve acetate,ethyl cellosolve acetate, diethylene glycol, diethylene glycolmonoacetate, diethylene glycol monomethyl ether, diethylene glycoldiethyl ether, diethylene glycol dimethyl ether, diethylene glycolethylmethyl ether, dietherylene glycol monoethyl ether, diethyleneglycol monbutyl ether, ethyl 2-hydroxypropionate, methyl2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethylethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-2-methylbutanate,methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl acetate, butylacetate, methyl lactate and ethyl lactate, propylene glycol, propyleneglycol monoacetate, propylene glycol monoethyl ether acetate, propyleneglycol monomethyl ether acetate, propylene glycol monopropyl methylether acetate, propylene glycol monobutyl ether acetate, propyleneglycol monobutyl ether acetate, propylene glycol monomethyl etherpropionate, propylene glycol monoethyl ether propionate, proplyelenglycol methyl ether adcetate, proplylene glycol ethyl ether acetate,ethylene glycol monomethyl ether acetate, ethylene glycol monoethylether acetate, propylene glycol monomethyl ether, propylene glycolmonoethyl ether, propylene glycol monopropyl ether, propylene glycolmonobutyl ether, ethylene glycol monomethyl ether, ethylene glycolmonoethyl ether, methyl lactate, ethyl lactate, propyl lactate, andbutyl lactate, ethyl 3-ethoxypropionate, methyl 3-methoxypropionate,methyl 3-ethoxypropionate, and ethyl 3-methoxypropionate,β-propiolactone, β-butyrolactone, γ-butyrolactone,α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ-valerolactone,γ-caprolactone, γ-octanoic lactone, α-hydroxy-γ-butyrolactone,2-butanone, 3-methylbutanone, pinacolone, 2-pentanone, 3-pentanone,4-methyl-2-pentanone, 2-methyl-3-pentanone, 4,4-dimethyl-2-pentanone,2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone, 2-hexanone,3-hexanone, 5-methyl-3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone,2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4-heptanone,2-octanone, 3-octanone, 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone,3-decanone, 4-decanone, 5-hexene-2-one, 3-pentene-2-one, cyclopentanone,2-methylcyclopentanone, 3-methylcyclopentanone,2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopentanone,cyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone,4-ethylcyclohexanone, 2,2-dimethylcyclohexanone,2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone,2-methylcycloheptanone, 3-methylcycloheptanone, pylene carbonate,vinylene carbonate, ethylene carbonate, and butylene carbonate,acetate-2-methoxyethyl, acetate-2-ethoxyethyl,acetate-2-(2-ethoxyethoxy)ethyl, acetate-3-methoxy-3-methylbutyl,acetate-1-methoxy-2-propyl, dipropylene glycol, monomethylether,monoethylether, monopropylether, monobutylehter, monopheylether,dipropylene glycol monoacetate, dioxane, methyl lactate, etheyl lactate,methyl acetate, ethyl acetate, butyl acetate, methyl puruvate, ethylpuruvate, propyl pyruvate, methyl methoxypropionate, ethylethoxypropionate, n-methylpyrrolidone (NMP), 2-methoxyethyl ether(diglyme), ethylene glycol monom-ethyl ether, propylene glycolmonomethyl ether; ethyl lactate or methyl lactate, methyl proponiate,ethyl proponiate and ethyl ethoxy proponiate, methylethyl ketone,cyclohexanone, 2-heptanone, carbon dioxide, cyclopentatone,cyclohexanone, ethyl 3-ethocypropionate, ethyl lactate, propylene glycolmethyl ether acetate (PGMEA), methylene cellosolve, butyle acetate, and2-ethoxyethanol, N-methylformamide, N,N-dimethylformamide,N-methylformanilide, N-methylacetamide, N,N-dimethylacetamide,N-methylpyrrolidone, dimethylsulfoxide, benzyl ethyl ether, dihexylether, acetonylacetone, isophorone, caproic acid, caprylic acid,1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate,diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate,propylene carbonate, phenyl cellosolve acetate, or the like.

However, as one of ordinary skill in the art will recognize, thematerials listed and described above as examples of materials that maybe utilized for the photoresist solvent component of the photoresist 701are merely illustrative and are not intended to limit the embodiments.Rather, any suitable material that may dissolve the photoresist polymerresin and the PACs may alternatively be utilized to help mix and applythe photoresist 701. All such materials are fully intended to beincluded within the scope of the embodiments.

Additionally, while individual ones of the above described materials maybe used as the photoresist solvent for the photoresist 701, inalternative embodiments more than one of the above described materialsmay be utilized. For example, the photoresist solvent may comprise acombination mixture of two or more of the materials described. All suchcombinations are fully intended to be included within the scope of theembodiments.

Optionally, a photoresist cross-linking agent may also be added to thephotoresist 701. The photoresist cross-linking agent reacts with thephotoresist polymer resin within the photoresist 701 after exposure,assisting in increasing the cross-linking density of the photoresist,which helps to improve the resist pattern and resistance to dry etching.In an embodiment the photoresist cross-linking agent may be an melaminebased agent, a urea based agent, ethylene urea based agent, propyleneurea based agent, glycoluril based agent, an aliphatic cyclichydrocarbon having a hydroxyl group, a hydroxyalkyl group, or acombination of these, oxygen containing derivatives of the aliphaticcyclic hydrocarbon, glycoluril compounds, etherified amino resins,combinations of these, or the like.

Specific examples of materials that may be utilized as a photoresistcross-linking agent include melamine, acetoguanamine, benzoguanamine,urea, ethylene urea, or glycoluril with formaldehyde, glycoluril with acombination of formaldehyde and a lower alcohol,hexamethoxymethylmelamine, bismethoxymethylurea,bismethoxymethylbismethoxyethylene urea, tetramethoxymethylglycoluril,and tetrabutoxymethylglycoluril, mono-, di-, tri-, ortetra-hydroxymethylated glycoluril, mono-, di-, tri-, and/ortetra-methoxymethylated glycoluril, mono-, di-, tri-, and/ortetra-ethoxymethylated glycoluril, mono-, di-, tri-, and/ortetra-propoxymethylated glycoluril, and mono-, di-, tri-, and/ortetra-butoxymethylated glycoluril,2,3-dihydroxy-5-hydroxymethylnorbornane,2-hydroy-5,6-bis(hydroxymethyl)norbornane, cyclohexanedimethanol,3,4,8(or 9)-trihydroxytricyclodecane, 2-methyl-2-adamantanol,1,4-dioxane-2,3-diol and 1,3,5-trihydroxycyclohexane, tetramethoxymethylglycoluril, methylpropyltetramethoxymethyl glycoluril, andmethylphenyltetramethoxymethylglycoluril,2,6-bis(hydroxymethyl)p-cresol, N-methoxymethyl- orN-butoxymethyl-melamine. Additionally, compounds obtained by reactingformaldehyde, or formaldehyde and lower alcohols with aminogroup-containing compounds, such as melamine, acetoguanamine,benzoguanamine, urea, ethylene urea and glycoluril, and substituting thehydrogen atoms of the amino group with hydroxymethyl group or loweralkoxymethyl group, examples being hexamethoxymethylmelamine,bismethoxymethyl urea, bismethoxymethylbismethoxyethylene urea,tetramethoxymethyl glycoluril and tetrabutoxymethyl glycoluril,copolymers of 3-chloro-2-hydroxypropyl methacrylate and methacrylicacid, copolymers of 3-chloro-2-hydroxypropyl methacrylate and cyclohexylmethacrylate and methacrylic acid, copolymers of3-chloro-2-hydroxypropyl methacrylate and benzyl methacrylate andmethacrylic acid, bisphenol A-di(3-chloro-2-hydroxypropyl)ether,poly(3-chloro-2-hydroxypro-pyl)ether of a phenol novolak resin,pentaerythritol tetra(3-chloro-2-hydroxypropyl)ether, trimethylolmethanetri(3-chloro-2-hydroxypropyl)ether phenol, bisphenolA-di(3-acetoxy-2-hydroxypropyl)ether,poly(3-acetoxy-2-hydroxypropyl)ethe-r of a phenol novolak resin,pentaerythritol tetra(3-acetoxy-2-hydroxyprop-yl)ether, pentaerythritolpoly(3-chloroacetoxy-2-hydroxypropyl)ether, trimethylolmethanetri(3-acetoxy-2-hydroxypropyl)ether, combinations of these, or the like.

In addition to the photoresist polymer resins, the PACs, the photoresistsolvents, and the photoresist cross-linking agents, the photoresist 701may also include a number of other additives that will assist thephotoresist 701 obtain the highest resolution. For example, thephotoresist 701 may also include surfactants in order to help improvethe ability of the photoresist 701 to coat the surface on which it isapplied. In an embodiment the surfactants may include nonionicsurfactants, polymers having fluorinated aliphatic groups, surfactantsthat contain at least one fluorine atom and/or at least one siliconatom, polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers,polyoxyethylene-polyoxypropylene block copolymers, sorbitan fatty acidesters, polyoxyethylene sorbitan fatty acid esters.

Specific examples of materials that may be used as surfactants includepolyoxyethylene lauryl ether, polyoxyethylene stearyl ether,polyoxyethylene cetyl ether, polyoxyethylene oleyl ether,polyoxyethylene octyl phenol ether, polyoxyethylene nonyl phenol ether,sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate,sorbitan monooleate, sorbitan trioleate, sorbitan tristearate,polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitanmonopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylenesorbitan trioleate, polyoxyethylene sorbitan tristearate, polyethyleneglycol distearate, polyethylene glycol dilaurate, polyethylene glycoldilaurate, polyethylene glycol, polypropylene glycol,polyoxyethylenestearyl ether and polyoxyethylene cetyl ether; fluorinecontaining cationic surfactants, fluorine containing nonionicsurfactants, fluorine containing anionic surfactants, cationicsurfactants and anionic surfactants, polyethylene glycol, polypropyleneglycol, polyoxyethylene cetyl ether, combinations of these, or the like.

Another additive that may be added to the photoresist 701 is a quencher,which may be utilized to inhibit diffusion of the generatedacids/bases/free radicals within the photoresist, which helps the resistpattern configuration as well as to improve the stability of thephotoresist 701 over time. In an embodiment the quencher is an aminesuch as a second lower aliphatic amine, a tertiary lower aliphaticamine, or the like. Specific examples of amines that may be used includetrimethylamine, diethylamine, triethylamine, di-n-propylamine,tri-n-propylamine, tripentylamine, diethanolamine, and triethanolamine,alkanolamine, combinations of these, or the like.

Alternatively, an organic acid may be utilized as the quencher. Specificembodiments of organic acids that may be utilized include malonic acid,citric acid, malic acid, succinic acid, benzoic acid, salicylic acid,phosphorous oxo acid and its derivatives such as phosphoric acid andderivatives thereof such as its esters, such as phosphoric acid,phosphoric acid di-n-butyl ester and phosphoric acid diphenyl ester;phosphonic acid and derivatives thereof such as its ester, such asphosphonic acid, phosphonic acid dimethyl ester, phosphonic aciddi-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester,and phosphonic acid dibenzyl ester; and phosphinic acid and derivativesthereof such as its esters, including phosphinic acid andphenylphosphinic acid.

Another additive that may be added to the photoresist 701 is astabilizer, which assists in preventing undesired diffusion of the acidsgenerated during exposure of the photoresist 701. In an embodiment thestabilizer may include nitrogenous compounds such as aliphatic primary,secondary, and tertiary amines, cyclic amines such as piperidines,pyrrolidines, morpholines, aromatic heterocycles such as pyridines,pyrimidines, purines, imines such as diazabicycloundecene, guanidines,imides, amides, and others. Alternatively, ammonium salts may also beused for the stabilizer, including ammonium, primary, secondary,tertiary, and quaternary alkyl- and arylammonium salts of alkoxidesincluding hydroxide, phenolates, carboxylates, aryl and alkylsulfonates, sulfonamides, and others. Other cationic nitrogenouscompounds including pyridinium salts and salts of other heterocyclicnitrogenous compounds with anions such as alkoxides including hydroxide,phenolates, carboxylates, aryl and alkyl sulfonates, sulfonamides, andthe like may also be employed.

Yet another additive that may be added to the photoresist 701 may be adissolution inhibitor in order to help control dissolution of thephotoresist 701 during development. In an embodiment bile-salt estersmay be utilized as the dissolution inhibitor. Specific examples ofmaterials that may be utilized include cholic acid (IV), deoxycholicacid (V), lithocholic acid (VI), t-butyl deoxycholate (VII), t-butyllithocholate (VIII), and t-butyl-3-α-acetyl lithocholate (IX).

Another additive that may be added to the photoresist 701 may be aplasticizer. Plasticizers may be used to reduce delamination andcracking between the photoresist 701 and underlying layers (e.g., theBARC layer 105) and may comprise monomeric, loigomeric, and polymericplasticizers such as oligo-anpolyethyleneglycol ethers, cycloaliphaticesters, and non-acid reactive steroidally-derived materials. Specificexamples of materials that may be used for the plasticizer includedioctyl phthalate, didodecyl phthalate, triethylene glycol dicaprylate,dimethyl glycol phthalate, tricresyl phosphate, dioctyl adipate, dibutylsebacate, triacetyl glycerine and the like.

Yet another additive that may be added include a coloring agent, whichhelps observers examine the photoresist 701 and find any defects thatmay need to be remedied prior to further processing. In an embodimentthe coloring agent may be either a triarylmethane dye or, alternatively,may be a fine particle organic pigment. Specific examples of materialsthat may be used as coloring agents include crystal violet, methylviolet, ethyl violet, oil blue #603, Victoria Pure Blue BOH, malachitegreen, diamond green, phthalocyanine pigments, azo pigments, carbonblack, titanium oxide, brilliant green dye (C. I. 42020), Victoria PureBlue FGA (Linebrow), Victoria BO (Linebrow) (C. I. 42595), Victoria BlueBO (C. I. 44045) rhodamine 6G (C. I. 45160), Benzophenone compounds suchas 2,4-dihydroxybenzophenone and 2,2′,4,4′-tetrahydroxybenzophenone,salicylic acid compounds such as phenyl salicylate and 4-t-butylphenylsalicylate, phenylacrylate compounds such asethyl-2-cyano-3,3-diphenylacrylate, and2′-ethylhexyl-2-cyano-3,3-diphenylacrylate, benzotriazole compounds suchas 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, and2-(3-t-butyl-2-hydroxy-5-methylphenyl)-5-chloro-2H-benzotriazole,coumarin compounds such as 4-methyl-7-diethylamino-1-benzopyran-2-one,thioxanthone compounds such as diethylthioxanthone, stilbene compounds,naphthalic acid compounds, azo dyes, Phthalocyanine blue, phthalocyaninegreen, iodine green, Victoria blue, crystal violet, titanium oxide,carbon black, naphthalene black, Photopia methyl violet, bromphenol blueand bromcresol green, laser dyes such as Rhodamine G6, Coumarin 500, DCM(4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H pyran)),Kiton Red 620, Pyrromethene 580, or the like. Additionally, one or morecoloring agents may be used in combination to provide the desiredcoloring.

Adhesion additives may also be added to the photoresist 701 in order topromote adhesion between the photoresist 701 and an underlying layerupon which the photoresist 701 has been applied (e.g., the BARC layer105). In an embodiment the adhesion additives include a silane compoundwith at least one reactive substituent such as a carboxyl group, amethacryloyl group, an isocyanate group and/or an epoxy group. Specificexamples of the adhesion components include trimethoxysilyl benzoicacid, γ-methacryloxypropyl trimethoxy silane, vinyltriacetoxysilane,vinyltrimethoxysilane, γ-isocyanatepropyl triethoxy silane,γ-glycidoxypropyl trimethoxy silane, β-(3,4-epoxycyclohexyl)ethyltrimethoxy silane, benzimidazoles and polybenzimidazoles, a lowerhydroxyalkyl substituted pyridine derivative, a nitrogen heterocycliccompound, urea, thiourea, an organophosphorus compound, 8-oxyquinoline,4-hydroxypteridine and derivatives, 1,10-phenanthroline and derivatives,2,2′-bipyridine and derivatives, benzotriazoles; organophosphoruscompounds, phenylenediamine compounds, 2-amino-1-phenylethanol,N-phenylethanolamine, N-ethyldiethanolamine, N-ethylethanolamine andderivatives, benzothiazole, and a benzothiazoleamine salt having acyclohexyl ring and a morpholine ring,3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane,3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane,3-methacryloyloxypropyltrimethoxysilane, vinyl trimethoxysilane,combinations of these, or the like.

Surface leveling agents may additionally be added to the photoresist 701in order to assist a top surface of the photoresist 701 to be level sothat impinging light will not be adversely modified by an unlevelsurface. In an embodiment surface leveling agents may includefluoroaliphatic esters, hydroxyl terminated fluorinated polyethers,fluorinated ethylene glycol polymers, silicones, acrylic polymerleveling agents, combinations of these, or the like.

In an embodiment the photoresist polymer resin and the PACs, along withany desired additives or other agents, are added to the photoresistsolvent for application. Once added, the mixture is then mixed in orderto achieve an even composition throughout the photoresist 701 in orderto ensure that there are no defects caused by an uneven mixing ornon-constant composition of the photoresist 701. Once mixed together,the photoresist 701 may either be stored prior to its usage or else usedimmediately.

Once ready, the photoresist 701 may be utilized by initially applyingthe photoresist 701 onto the BARC layer 105. The photoresist 701 may beapplied to the BARC layer 105 so that the photoresist 701 coats an upperexposed surface of the BARC layer 105, and may be applied using aprocess such as a spin-on coating process, a dip coating method, anair-knife coating method, a curtain coating method, a wire-bar coatingmethod, a gravure coating method, a lamination method, an extrusioncoating method, combinations of these, or the like. In an embodiment thephotoresist 701 may be applied such that it has a thickness over thesurface of the BARC layer 105 of between about 10 nm and about 300 nm,such as about 150 nm.

Once the photoresist 701 has been applied to the semiconductorsubstrate, a pre-bake of the photoresist 701 is performed in order tocure and dry the photoresist 701 prior to exposure to finish theapplication of the photoresist 701. The curing and drying of thephotoresist 701 removes the photoresist solvent component while leavingbehind the photoresist polymer resin, the PACs, the photoresistcross-linking agents, and the other chosen additives. In an embodimentthe pre-bake may be performed at a temperature suitable to evaporate thephotoresist solvent, such as between about 40° C. and 150° C., althoughthe precise temperature depends upon the materials chosen for thephotoresist 701. The pre-bake is performed for a time sufficient to cureand dry the photoresist 701, such as between about 10 seconds to about 5minutes, such as about 90 seconds.

Once applied, the photoresist 701 may be exposed to form an exposedregion 703 and an unexposed region 705 within the photoresist 701. In anembodiment the exposure may be initiated by placing the substrate 101and the photoresist 701, once cured and dried, into a photoresistimaging device 700 for exposure. The photoresist imaging device 700 maycomprise a photoresist support plate 704, a photoresist energy source707, a patterned mask 709 between the photoresist support plate 704 andthe photoresist energy source 707, and photoresist optics 713. In anembodiment the photoresist support plate 704 is a surface to which thesemiconductor device 100 and the photoresist 701 may be placed orattached to and which provides support and control to the substrate 101during exposure of the photoresist 701. Additionally, the photoresistsupport plate 704 may be movable along one or more axes, as well asproviding any desired heating or cooling to the substrate 101 andphotoresist 701 in order to prevent temperature gradients from affectingthe exposure process.

In an embodiment the photoresist energy source 707 supplies photoresistenergy 711 such as light to the photoresist 701 in order to induce areaction of the PACs, which in turn reacts with the photoresist polymerresin to chemically alter those portions of the photoresist 701 to whichthe photoresist energy 711 impinges. In an embodiment the photoresistenergy 711 may be electromagnetic radiation, such as g-rays (with awavelength of about 436 nm), i-rays (with a wavelength of about 365 nm),ultraviolet radiation, far ultraviolet radiation, x-rays, electronbeams, or the like. The photoresist energy source 707 may be a source ofthe electromagnetic radiation, and may be a KrF excimer laser light(with a wavelength of 248 nm), an ArF excimer laser light (with awavelength of 193 nm), a F2 excimer laser light (with a wavelength of157 nm), or the like, although any other suitable source of photoresistenergy 711, such as mercury vapor lamps, xenon lamps, carbon arc lampsor the like, may alternatively be utilized.

The patterned mask 709 is located between the photoresist energy source707 and the photoresist 701 in order to block portions of thephotoresist energy 711 to form a patterned energy 715 prior to thephotoresist energy 711 actually impinging upon the photoresist 701. Inan embodiment the patterned mask 709 may comprise a series of layers(e.g., substrate, absorbance layers, anti-reflective coating layers,shielding layers, etc.) to reflect, absorb, or otherwise block portionsof the photoresist energy 711 from reaching those portions of thephotoresist 701 which are not desired to be illuminated. The desiredpattern may be formed in the patterned mask 709 by forming openingsthrough the patterned mask 709 in the desired shape of illumination.

Optics (represented in FIG. 7A by the trapezoid labeled 713) may be usedto concentrate, expand, reflect, or otherwise control the photoresistenergy 711 as it leaves the photoresist energy source 707, is patternedby the patterned mask 709, and is directed towards the photoresist 701.In an embodiment the photoresist optics 713 comprise one or more lenses,mirrors, filters, combinations of these, or the like to control thephotoresist energy 711 along its path. Additionally, while thephotoresist optics 713 are illustrated in FIG. 7A as being between thepatterned mask 709 and the photoresist 701, elements of the photoresistoptics 713 (e.g., individual lenses, mirrors, etc.) may also be locatedat any location between the photoresist energy source 707 (where thephotoresist energy 711 is generated) and the photoresist 701.

In an embodiment the semiconductor device 100 with the photoresist 701is placed on the photoresist support plate 704. Once the pattern hasbeen aligned to the semiconductor device 100, the photoresist energysource 707 generates the desired photoresist energy 711 (e.g., light)which passes through the patterned mask 709 and the photoresist optics713 on its way to the photoresist 701. The patterned energy 715impinging upon portions of the photoresist 701 induces a reaction of thePACs within the photoresist 701. The chemical reaction products of thePACs' absorption of the patterned energy 715 (e.g., acids/bases/freeradicals) then reacts with the photoresist polymer resin, chemicallyaltering the photoresist 701 in those portions that were illuminatedthrough the patterned mask 709.

In a specific example in which the patterned energy 715 is a 193 nmwavelength of light, the PAC is a photoacid generator, and the group tobe decomposed is a carboxylic acid group on the hydrocarbon structureand a cross linking agent is used, the patterned energy 715 will impingeupon the photoacid generator and the photoacid generator will absorb theimpinging patterned energy 715. This absorption initiates the photoacidgenerator to generate a proton (e.g., a H+ atom) within the photoresist701. When the proton impacts the carboxylic acid group on thehydrocarbon structure, the proton will react with the carboxylic acidgroup, chemically altering the carboxylic acid group and altering theproperties of the photoresist polymer resin in general. The carboxylicacid group will then react with the photoresist cross-linking agent tocross-link with other photoresist polymer resins within the photoresist701.

Optionally, the exposure of the photoresist 701 may occur using animmersion lithography technique. In such a technique an immersion medium(not individually illustrated in FIG. 2) may be placed between thephotoresist imaging device 700 (and particularly between a final lens ofthe photoresist optics 713) and the photoresist 701. With this immersionmedium in place, the photoresist 701 may be patterned with the patternedenergy 715 passing through the immersion medium.

In this embodiment a protective layer (also not individually illustratedin FIG. 2) may be formed over the photoresist 701 in order to preventthe immersion medium from coming into direct contact with thephotoresist 701 and leaching or otherwise adversely affecting thephotoresist 701. In an embodiment the protective layer is insolublewithin the immersion medium such that the immersion medium will notdissolve it and is immiscible in the photoresist 701 such that theprotective layer will not adversely affect the photoresist 701.Additionally, the protective layer is transparent so that the patternedenergy 715 may pass through the protective layer without hindrance.

In an embodiment the protective layer comprises a protective layer resinwithin a protective layer solvent. The material used for the protectivelayer solvent is, at least in part, dependent upon the components chosenfor the photoresist 701, as the protective layer solvent should notdissolve the materials of the photoresist 701 so as to avoid degradationof the photoresist 701 during application and use of the protectivelayer. In an embodiment the protective layer solvent includes alcoholsolvents, fluorinated solvents, and hydrocarbon solvents.

Specific examples of materials that may be utilized for the protectivelayer solvent include methanol, ethanol, 1-propanol, isopropanol,n-propanol, 1-butanol, 2-butanol, 2-methyl-2-propanol,3-methyl-1-butanol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol,2-pentanol, 3-pentanol, n-hexanol, cyclohecanol, 1-hexanol, 1-heptanol,1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol,3-octanol, 4-octanol, 2-methyl-2-butanol, 3-methyl-1-butanol,3-methyl-2-butanol, 2-methyl-1-butanol, 2-methyl-1-pentanol,2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol,3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol,4-methyl-2-pentanol, 2,2,3,3,4,4-hexafluoro-1-butanol,2,2,3,3,4,4,5,5-octafluoro-1-pentanol,2,2,3,3,4,4,5,5,6,6-decafluoro-1-hexanol,2,2,3,3,4,4-hexafluoro-1,5-pentanediol,2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol,2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoro-1,8-diol, 2-fluoroanisole,2,3-difluoroanisole, perfluorohexane, perfluoroheptane,perfluoro-2-pentanone, perfluoro-2-butyltetrahydrofuran,perfluorotetrahydrofuran, perfluorotributylamine,perfluorotetrapentylamine, toluene, xylene and anisole, and aliphatichydrocarbon solvents, such as n-heptane, n-nonane, n-octane, n-decane,2-methylheptane, 3-methylheptane, 3,3-dimethylhexane,2,3,4-trimethylpentane, combinations of these, or the like.

The protective layer resin may, similar to the photoresist 701, comprisea protective layer repeating unit. In an embodiment the protective layerrepeating unit may be an acrylic resin with a repeating hydrocarbonstructure having a carboxyl group, an alicyclic structure, an alkylgroup having one to five carbon atoms, a phenol group, or a fluorineatom-containing group. Specific examples of the alicyclic structureinclude a cyclohexyl group, an adamantyl group, a norbornyl group, anisobornyl group, a tricyclodecyl group, a tetracyclododecyl group, andthe like. Specific examples of the alkyl group include an n-butyl group,an isobutyl group, or the like. However, any suitable protective layerresin may alternatively be utilized.

The protective layer composition may also include additional additivesto assist in such things as adhesion, surface leveling, coating, and thelike. For example, the protective layer composition may further comprisea protective layer surfactant, although other additives may also beadded, and all such additions are fully intended to be included withinthe scope of the embodiment. In an embodiment the protective layersurfactant may be an alkyl cationic surfactant, an amide-type quaternarycationic surfactant, an ester-type quaternary cationic surfactant, anamine oxide surfactant, a betaine surfactant, an alkoxylate surfactant,a fatty acid ester surfactant, an amide surfactant, an alcoholsurfactant, an ethylenediamine surfactant, or a fluorine- and/orsilicon-containing surfactant.

Specific examples of materials that may be used for the protective layersurfactant include polyoxyethylene alkyl ethers, such as polyoxyethylenelauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl etherand polyoxyethylene oleyl ether; polyoxyethylene alkyl aryl ethers, suchas polyoxyethylene octyl phenol ether and polyoxyethylene nonyl phenolether; polyoxyethylene-polyooxypropylene block copolymers; sorbitanfatty acid esters, such as sorbitan monolaurate, sorbitan monopalmitate,sorbitan monostearate, sorbitan monooleate, sorbitan trioleate andsorbitan tristearate; and polyoxyethylene sorbitan monolaurate,polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitanmonostearate, polyoxyethylene sorbitan trioleate and polyoxyethylenesorbitan tristearate.

Prior to application of the protective layer onto the photoresist 701,the protective layer resin and desired additives are first added to theprotective layer solvent to form a protective layer composition. Theprotective layer solvent is then mixed to ensure that the protectivelayer composition has a consistent concentration throughout theprotective layer composition.

Once the protective layer composition is ready for application, theprotective layer composition may be applied over the photoresist 701. Inan embodiment the application may be performed using a process such as aspin-on coating process, a dip coating method, an air-knife coatingmethod, a curtain coating method, a wire-bar coating method, a gravurecoating method, a lamination method, an extrusion coating method,combinations of these, or the like. In an embodiment the photoresist 701may be applied such that it has a thickness over the surface of thephotoresist 701 of about 100 nm.

After the protective layer composition has been applied to thephotoresist 701, a protective layer pre-bake may be performed in orderto remove the protective layer solvent. In an embodiment the protectivelayer pre-bake may be performed at a temperature suitable to evaporatethe protective layer solvent, such as between about 40° C. and 150° C.,although the precise temperature depends upon the materials chosen forthe protective layer composition. The protective layer pre-bake isperformed for a time sufficient to cure and dry the protective layercomposition, such as between about 10 seconds to about 5 minutes, suchas about 90 seconds.

Once the protective layer has been placed over the photoresist 701, thesemiconductor device 100 with the photoresist 701 and the protectivelayer are placed on the photoresist support plate 704, and the immersionmedium may be placed between the protective layer and the photoresistoptics 713. In an embodiment the immersion medium is a liquid having arefractive index greater than that of the surrounding atmosphere, suchas having a refractive index greater than 1. Examples of the immersionmedium may include water, oil, glycerine, glycerol, cycloalkanols, orthe like, although any suitable medium may alternatively be utilized.

The placement of the immersion medium between the protective layer andthe photoresist optics 713 may be done using, e.g., an air knife method,whereby fresh immersion medium is applied to a region between theprotective layer and the photoresist optics 713 and controlled usingpressurized gas directed towards the protective layer to form a barrierand keep the immersion medium from spreading. In this embodiment theimmersion medium may be applied, used, and removed from the protectivelayer for recycling so that there is fresh immersion medium used for theactual imaging process.

However, the air knife method described above is not the only method bywhich the photoresist 701 may be exposed using an immersion method. Anyother suitable method for imaging the photoresist 701 using an immersionmedium, such as immersing the entire substrate 101 along with thephotoresist 701 and the protective layer, using solid barriers insteadof gaseous barriers, or using an immersion medium without a protectivelayer, may also be utilized. Any suitable method for exposing thephotoresist 701 through the immersion medium may be used, and all suchmethods are fully intended to be included within the scope of theembodiments.

After the photoresist 701 has been exposed to the patterned energy 715,a post-exposure baking may be used in order to assist in the generating,dispersing, and reacting of the acid/base/free radical generated fromthe impingement of the patterned energy 715 upon the PACs during theexposure. Such assistance helps to create or enhance chemical reactionswhich generate chemical differences between the exposed region 703 andthe unexposed region 705 within the photoresist 701. These chemicaldifferences also caused differences in the solubility between theexposed region 703 and the unexposed region 705. In an embodiment thispost-exposure baking may occur at temperatures of between about 50° C.and about 160° C. for a period of between about 40 seconds and about 120seconds.

FIG. 7B illustrates a development of the photoresist 701 with the use ofa developer 717 after the photoresist 701 has been exposed. After thephotoresist 701 has been exposed and the post-exposure baking hasoccurred, the photoresist 701 may be developed using either a positivetone developer or a negative tone developer, depending upon the desiredpattern for the photoresist 701. In an embodiment in which the exposedregion 703 of the photoresist 701 is desired to be removed to form apositive tone, a positive tone developer such as a basic aqueoussolution may be utilized to remove those portions of the photoresist 701which were exposed to the patterned energy 715 and which have had theirsolubility modified and changed through the chemical reactions. Suchbasic aqueous solutions may include tetra methyl ammonium hydroxide(TMAH), tetra butyl ammonium hydroxide, sodium hydroxide, potassiumhydroxide, sodium carbonate, sodium bicarbonate, sodium silicate, sodiummetasilicate, aqueous ammonia, monomethylamine, dimethylamine,trimethylamine, monoethylamine, diethylamine, triethylamine,monoisopropylamine, diisopropylamine, triisopropylamine, monobutylamine,dibutylamine, monoethanolamine, diethanolamine, triethanolamine,dimethylaminoethanol, diethylaminoethanol, ammonia, caustic soda,caustic potash, sodium metasilicate, potassium metasilicate, sodiumcarbonate, tetraethylammonium hydroxide, combinations of these, or thelike.

If a negative tone development is desired, an organic solvent orcritical fluid may be utilized to remove those portions of thephotoresist 701 which were not exposed to the energy and, as such,retain their original solubility. Specific examples of materials thatmay be utilized include hydrocarbon solvents, alcohol solvents, ethersolvents, ester solvents, critical fluids, combinations of these, or thelike. Specific examples of materials that can be used for the negativetone solvent include hexane, heptane, octane, toluene, xylene,dichloromethane, chloroform, carbon tetrachloride, trichloroethylene,methanol, ethanol, propanol, butanol, critical carbon dioxide, diethylether, dipropyl ether, dibutyl ether, ethyl vinyl ether, dioxane,propylene oxide, tetrahydrofuran, cellosolve, methyl cellosolve, butylcellosolve, methyl carbitol, diethylene glycol monoethyl ether, acetone,methyl ethyl ketone, methyl isobutyl ketone, isophorone, cyclohexanone,methyl acetate, ethyl acetate, propyl acetate, butyl acetate, pyridine,formamide, N,N-dimethyl formamide, or the like.

However, as one of ordinary skill in the art will recognize, the abovedescription of positive tone developers and negative tone developers areonly intended to be illustrative and are not intended to limit theembodiments to only the developers listed above. Rather, any suitabletype of developer, including acid developers or even water developers,that may be utilized to selectively remove a portion of the photoresist701 that has a different property (e.g., solubility) than anotherportion of the photoresist 701, may alternatively be utilized, and allsuch developers are fully intended to be included within the scope ofthe embodiments.

In an embodiment in which immersion lithography is utilized to exposethe photoresist 701 and a protective layer is utilized to protect thephotoresist 701 from the immersion medium, the developer 717 may bechosen to remove not only those portions of the photoresist 701 that aredesired to be removed, but may also be chosen to remove the protectivelayer in the same development step. Alternatively, the protective layermay be removed in a separate process, such as by a separate solvent fromthe developer 717 or even an etching process to remove the protectivelayer from the photoresist 701 prior to development.

FIG. 7B illustrates an application of the developer 717 to thephotoresist 701 using, e.g., a spin-on process. In this process thedeveloper 717 is applied to the photoresist 701 from above thephotoresist 701 while the semiconductor device 100 (and the photoresist701) is rotated. In an embodiment the developer 717 may be supplied at aflow rate of between about 100 c.c./min and about 2000 c.c./min, such asabout 600 c.c./min, while the semiconductor device 100 is being rotatedat a speed of between about 300 rpm and about 3000 rpm, such as about2000 rpm. In an embodiment the developer 717 may be at a temperature ofbetween about 10° C. and about 80° C., such as about 50° C., and thedevelopment may continue for between about 1 minute to about 60 minutes,such as about 30 minutes.

However, while the spin-on method described herein is one suitablemethod for developing the photoresist 701 after exposure, it is intendedto be illustrative and is not intended to limit the embodiments. Rather,any suitable method for development, including dip processes, puddleprocesses, and spray-on processes, may alternatively be used. All suchdevelopment processes are fully intended to be included within the scopeof the embodiments.

FIG. 7B illustrates a cross-section of the development process in anembodiment in which a negative tone developer is used to remove theunexposed regions of the photoresist 701. As illustrated, the developer717 is applied to the photoresist 701 and dissolves the unexposedportion 705 of the photoresist 701. This dissolving and removing of theunexposed portion 705 of the photoresist 701 leaves behind an openingwithin the photoresist 701 that patterns the photoresist 701 in theshape of the patterned energy 715, thereby transferring the pattern ofthe patterned mask 709 to the photoresist 701.

Once the photoresist 701 has been patterned, the pattern may betransferred to the BARC layer 105. In an embodiment in which the BARClayer 105 remains insoluble to the developer 717, the BARC layer 105 maybe removed using an etching process that utilizes the photoresist 701(now patterned) as a masking layer. The etching process may be a dryetch process utilizing an etchant such as oxygen, nitrogen, hydrogen,ammonia, sulfur hexafluoride, difluoromethane, nitrogen trifluoride,chlorine trifluoride, chlorine, carbon monoxide, carbon dioxide, helium,boron dichloride, argon, fluorine, trifluoromethane, tetrafluoromethane,perfluorocyclobutane, perfluoropropane, combinations of these, or thelike. However, any other suitable etch process, such as a wet etch, andany other suitable etchants may alternatively be used.

Alternatively, in an embodiment in which the BARC layer 105 comprises anacid labile group that can react to de-crosslink the cross-linkedpolymers in the BARC layer 105 and change the solubility of the BARClayer 105, the BARC layer 105 may be patterned during the developmentprocess by the developer 717. In particular, during exposure thephotoacid generators may generate an acid in the BARC layer 105, whichwill work to break the cross-linking bonds and change the solubility ofthe BARC layer 105. Then, in a positive tone development process, apositive tone developer may be used to remove both the photoresist 717that had been exposed as well as to remove the BARC layer 105 in thesame process. Any suitable patterning process, with any suitable numberof steps, may be utilized to pattern and remove both the photoresist 717and the BARC layer 105, and all such processes and steps are fullyintended to be included within the scope of the embodiments.

FIG. 8 illustrates another embodiment utilizing the BARC layer 105,instead of simply being utilized as an anti-reflective coating, isutilized as an underlayer used along with a hard mask layer 801. In suchan embodiment the BARC layer 105 may be formed as described above withrespect to FIG. 1. Once formed, however, instead of placing thephotoresist 701 directly on the BARC layer 105, a hard mask layer 801 isformed on the BARC layer 801.

In an embodiment the hard mask layer 801 may be a hardmask material suchas silicon nitride, oxides, oxynitrides, silicon carbide, combinationsof these, or the like. The hardmask material for the hard mask layer 801may be formed through a process such as chemical vapor deposition (CVD),although other processes, such as plasma enhanced chemical vapordeposition (PECVD), low pressure chemical vapor deposition (LPCVD),spin-on coating, or even silicon oxide formation followed bynitridation, may alternatively be utilized. Any suitable method orcombination of methods to form or otherwise place the hardmask materialmay be utilized, and all such methods or combination are fully intendedto be included within the scope of the embodiments. The hard mask layer801 may be formed to a thickness of between about 100 Å and about 800 Å,such as about 300 Å.

Once a layer of the hardmask material for the hard mask layer 801 hasbeen formed, the photoresist 701 may be placed and patterned over thehard mask material for the hard mask layer 801. The placement of thephotoresist 701 over the hard mask material for the hard mask layer 801and the patterning of the photoresist 701 may be similar to theplacement of the photoresist 701 and the development of the photoresistas described above with respect to FIG. 7A-7B. For example, thephotoresist 701 may be placed using a spin-on process, illuminated usingthe photoresist imaging device 700, and then developed using thedeveloper 717.

FIG. 8B illustrates that, once the photoresist 701 has been patternedinto the desired pattern, the photoresist 701 may be used as a mask topattern the hard mask material of the hard mask layer 801. For example,the pattern of the photoresist 701 may be transferred to the hard masklayer 801 using a anisotropic etching process such as reactive ionetching (RIE), whereby ions of a suitable etchant such as CF₄—O₂, may beutilized in a dry etch to remove portions of the hard mask layer 801exposed by the patterned photoresist 701. However, any other suitableetchant, such as CHF₂/O₂, CH₂F₂, CH₃F, or the like, and any othersuitable method of removal, may alternatively be used.

FIG. 8B further illustrates that once the pattern of the photoresist 701has been transferred to the hard mask 801, the hard mask 801 may be usedto transfer the pattern of the photoresist 701 to the BARC layer 105. Inan embodiment the BARC layer 105 may be removed using an etching processthat utilizes the photoresist 701 and the hard mask 801 (now patterned)as a masking layer. The etching process may be a dry etch processutilizing an etchant such as oxygen, nitrogen, hydrogen, ammonia, sulfurhexafluoride, difluoromethane, nitrogen trifluoride, chlorinetrifluoride, chlorine, carbon monoxide, carbon dioxide, helium, borondichloride, argon, fluorine, trifluoromethane, tetrafluoromethane,perfluorocyclobutane, perfluoropropane, combinations of these, or thelike. However, any other suitable etch process, such as a wet etch, andany other suitable etchants may alternatively be used.

By utilizing the BARC layer 105 as an underlayer and just as ananti-reflective coating, a more uniform layer may be formed over avariety of different underlying terrains. By creating a more uniformlayer, subsequent processing may be better controlled, leading to a moreefficient manufacturing process capable of making devices with smallerand smaller dimensions.

In accordance with an embodiment, a method for manufacturing asemiconductor device comprising applying an anti-reflective coatinglayer onto a substrate, the anti-reflective coating layer comprising aresin with a locked monomer is provided. The volume of theanti-reflective coating layer is expanded by unlocking the lockedmonomer.

In accordance with an embodiment, a method of manufacturing asemiconductor device applying an anti-reflective coating to a substrate,the anti-reflective coating comprising a polymer resin with repeatingunits, wherein at least one of the repeating units comprises a locklocated within a cyclic structure, is provided. A chemically reactivespecies is generated from a catalyst within the anti-reflective coating,the chemically reactive species cleaving the lock to break the cyclicstructure.

In accordance with an embodiment, an anti-reflective material comprisinga polymer resin, wherein the polymer resin comprises a locked cyclicstructure and a catalyst is provided. The catalyst can generate achemically reactive species capable of unlocking the locked cyclicstructure.

Although the present embodiments and their advantages have beendescribed in detail, it should be understood that various changes,substitutions and alterations can be made herein without departing fromthe spirit and scope of the disclosure as defined by the appendedclaims. For example, many different monomers may be used to form thematerial of the BARC layer 105, and may different processes may beutilized to form, apply, and develop the photoresist.

Moreover, the scope of the present application is not intended to belimited to the particular embodiments of the process, machine,manufacture, composition of matter, means, methods and steps describedin the specification. As one of ordinary skill in the art will readilyappreciate from the disclosure, processes, machines, manufacture,compositions of matter, means, methods, or steps, presently existing orlater to be developed, that perform substantially the same function orachieve substantially the same result as the corresponding embodimentsdescribed herein may be utilized according to the present disclosure.Accordingly, the appended claims are intended to include within theirscope such processes, machines, manufacture, compositions of matter,means, methods, or steps.

What is claimed is:
 1. A method for manufacturing a semiconductordevice, the method comprising: applying an anti-reflective coating layeronto a substrate, the anti-reflective coating layer comprising a resinwith a locked monomer; and expanding a volume of the anti-reflectivecoating layer by unlocking the locked monomer.
 2. The method of claim 1,wherein the unlocking the locked monomer comprises exposing theanti-reflective coating to an energy source.
 3. The method of claim 2,wherein the exposing the anti-reflective coating to an energy sourcegenerates an acid from a photoacid generator within the anti-reflectivecoating layer.
 4. The method of claim 2, wherein the exposing theanti-reflective coating to an energy source generates a base from aphotobase generator within the anti-reflective coating layer.
 5. Themethod of claim 1, wherein the unlocking the locked monomer comprisesheat treating the anti-reflective coating to generate an acid from athermal acid generator.
 6. The method of claim 1, wherein the lockedmonomer comprises a cyclic structure with a lock located within thecyclic structure.
 7. The method of claim 6, wherein the lock is anester.
 8. A method of manufacturing a semiconductor device, the methodcomprising: applying an anti-reflective coating to a substrate, theanti-reflective coating comprising a polymer resin with repeating units,wherein at least one of the repeating units comprises a lock locatedwithin a cyclic structure; and generating a chemically reactive speciesfrom a catalyst within the anti-reflective coating, the chemicallyreactive species cleaving the lock to break the cyclic structure.
 9. Themethod of claim 8, wherein the lock is an ester.
 10. The method of claim8, wherein the generating the chemically reactive species comprisesexposing the anti-reflective coating to an energy source.
 11. The methodof claim 8, wherein the catalyst is a photoacid generator.
 12. Themethod of claim 8, wherein the catalyst is a photobase generator. 13.The method of claim 8, further comprising performing a first bake tocross-link the polymer resin.
 14. The method of claim 13, wherein thegenerating the chemically reactive species comprises performing a secondbake different from the first bake to generate an acid from a thermalacid generator.
 15. An anti-reflective material comprising: a polymerresin, wherein the polymer resin comprises a locked cyclic structure;and a catalyst, wherein the catalyst can generate a chemically reactivespecies capable of unlocking the locked cyclic structure.
 16. Theanti-reflective material of claim 15, wherein the locked cyclicstructure comprises a lock with the following structure:

wherein Rx, Rz, or Ry is a hydrogen, halogen, an alkyl group having acarbon number of 1 to 20, an aminoalkyl group having a carbon number of1 to 20, an alkyloxy group having a carbon number of 1 to 20, anaminoalkyl group having a carbon number of 1 to 20, a hydroxyalkyl grouphaving a carbon number of 1 to 20, a substituted or unsubstituted arylgroup having a carbon number of 1 to 20, or a thioalkyl group having acarbon number of 1 to
 20. 17. The anti-reflective material of claim 15,wherein the locked cyclic structure comprises a lock with the followingstructure:

wherein Ra is an alkyl group having a carbon number of 1 to 20, anaminoalkyl group having a carbon number of 1 to 20, an alkoxy grouphaving a carbon number of 1 to 20, a hydroxyalkyl group having a carbonnumber of 1 to 20, a substituted or unsubstituted aryl group having acarbon number of 1 to 20, or a thioalkyl group having a carbon number of1 to
 20. 18. The anti-reflective material of claim 15, wherein thelocked cyclic structure comprises a lock with the following structure:

wherein Rx is a hydrogen, halogen, an alkyl group having a carbon numberof 1 to 20, an aminoalkyl group having a carbon number of 1 to 20, analkoxy group having a carbon number of 1 to 20, a hydroxyalkyl grouphaving a carbon number of 1 to 20, a substituted or unsubstituted arylgroup having a carbon number of 1 to 20, or a thioalkyl group having acarbon number of 1 to 20; and wherein Ra is an alkyl group having acarbon number of 1 to 20, an aminoalkyl group having a carbon number of1 to 20, an alkyloxy group having a carbon number of 1 to 20, ahydroxyalkyl group having a carbon number of 1 to 20, a substituted orunsubstituted aryl group having a carbon number of 1 to 20, or athioalkyl group having a carbon number of 1 to
 20. 19. Theanti-reflective material of claim 15, wherein the locked cyclicstructure comprises the following structure:


20. The anti-reflective material of claim 15, further comprising across-linking agent.